I'd be out of there.

I would not allow her in my home anymore. And never let your son out of sight when she is around again.

I would seriously banish my SD if she did something like that.

That is scary. I would never leave my child alone with her again. It sounds like the girl needs counseling to talk through her jealousy or anger issues or whatever. The catch 22 you're in is that if you do leave DH, unless you can convince a court the SD is a danger to your DS and should be carefully supervised around him (& it sounds like you'd have resistance from your DH on that), then your DS would have visitation with DH and SD present without you there to protect him.

You need to have a "come to Jesus" conversation with your SO. He either gets on board and gets SD into counseling, or you are going to take your baby and leave. Be prepared to leave to get the message across. This would be hard enough to deal with even if you had his support - but he since he doesn't believe SD actually hurt your son on purpose - you are in an impossible situation. This is at least the second time she has purposely hurt your son.

Your SO is not an amazing Dad. An amazing Dad does not give his child Tylenol every day and an amazing Dad does not prevent his daughter from getting the therapy that she so obviously needs.

Having to watch your baby 24/7 because you are scared of your SD seriously hurting him is no way to live.   Your DH is certainly not "amazing" - he is living in deep denial about what his daughter is capable of.  This is not doing her any favours - she needs help to deal with her violent impulses.  If he is not willing to drop his refusal to see this, then I would take the baby and leave. 

in the sense that he doesn't see his kid from the holy failed first family as a budding Jeffrina Dahmer.

To be abrupt, you're letting your "love" for this guy cloud your maternal protective instincts for your own child.

What will Daaaddeeeee say when his spawn shoves your baby down the stairs, trips him, tries to suffocate him, etc?

Even with nanny cam evidence?  Let me guess "she wouldn't do thaaaat."  

My formerSO's kid hurt and attempted to hurt my baby. I left to protect him.

FormerSO was the same, he "couldn't" believe his son hurt/tried to him on purpose and would come up with rediculous excuses. Like the MULTIPLE times I found broken glass all over baby's play areas....Oooooh the ceiling fan was on too high and the vibration probably caused the light fixture to chip. What?! Never mind it happened multiple times and it was WAY more glass than would come from the entire fixture completely broken. Oh and the remnants of a broken drinking glass in kid's room. His kid was 13, not sure how old your husband's kid is.

I know first hand how completey exhausting it is trying to keep an eagle eye watch. Even when my baby was sleeping, I had to stay in the room or keep a constant watch on the baby monitor. His kid SNUCK in baby's room several time and I would have to rush in.... When asked why..."he didnt know" or wouldn't say anything and just walk away. I had to take my baby to the bathroom with me; I couldn't leave for even short periods or suddenly baby would be crying with him standing there. 

Lay the law down. Force that kid into therapy or leave with your baby. It will NOT get better on it's own...it WILL get worse. 

OP, your DH is in denial about SD and you are in denial about DH.  He is not amazing at all if he's not protecting his son and not getting the help for his daughter that she needs. At some point, she could cause irreversible harm to your child (he could have lost his finger from being slammed in the door).  She needs a therapist to help her deal with the loss of her mother and how that's affecting her.

It's clear you don't want to leave - but I'd demand marriage counseling at the very least, so you can get on the same page about protecting your son and helping SD.

In addition to counseling for SD, what about seeing a counselor yourself?  It's not normal to allow your SO to gaslight you about his SD to the point your own child is getting hurt.  He is NOT an amazing man.  He is a terrible parent regardless of what you feel is love for his offspring (hint - love doesn't allow some of his kids to hurt others without dealing with what are clearly severe problems this girl is having!)

I'm very concerned you have alllowed this man to cloud your vision.  His child is a danger and he is too much of a mushy headed jerk to deal with it.

Is this a very young child here?  I tried to go back and skim your blogs and the only thing I saw was your bio mentioning 3yo.. but not sure if that is her age now.. or years ago.  

If the child is super young, like 5-6 or below.. in a way, I am not sure I would put 100% stock in her doing things on purpose.  kindof akin to a kid saying "I'm glad you are hurt" when they, themselves are feeling hurt.. even if they didn't do something intentional.  Then there is the issue of she could be very jealous of the baby and acting out.  I mean, kids will hit out at each other.. I know, for a fact, both my brother and myself have literal scars from each other from mishaps and tussles growing up.

I am definitely not trying to say that a child hurting another child is "ok".. but it is not abnormal and it happens quite often even when there isn't any Stepland involved.  So, maybe trying to put it into a little more perspective there. 

What does sound like something that needs to happen is that there needs to be more supervision of the children until the little one is able to "hold their own" with their older sibling.  Of course SD should get a consequence for hurting her sibling.. even if it may have been unintentional... even if it is only for the fact that one of the kids was hurt and she knew and didn't get an adult.  A "one day" grounding doesn't seem too extreme.

Your husband needs to understand that discipline is not picking on a child.. it's teaching them right from wrong.  If the child is older.. than 8 then this is super troubling as a child should start to develop a higher level of executive function and be able to control impulses and deal with losses without lashing out.

But.. things like a kid hitting out when another child pulls their hair.. that is kind of instinctive when they are very small...but given the history, certainly the adults need to be a bit more vigalent since the younger child isn't able to take care of it's own interests quite yet.

There is nothing I can add that hasn't already been said.

Your H is not an amazing dad- if he was he would be seeking help for his daughter and protecting his baby.

Your H is not an amazing husband- if he was he would make sure that you weren't alone in this.

OP- I hope you listen to what is being said here. As hard and as scary as this all is you have a couple of choices and they will all be hard.

1- Leave. Plain and simple, keep your baby safe- demand only supervised visits until SD has completed counseling and it is determined that she is safe to be around the baby.

2- Get her in counseling whether or no your H agrees. Draw a line in the sand and say it is counseling or me. Be prepared for him to say goodbye. He can't believe that something is wrong with her- that is a MAJOR ego red flag btw.

3- Live on pins and needles for the rest of your life in constant fear that your SD could do real and permanent harm to your baby. 

I am sorry to hear all this. Your poor child. He most certainly is not an amazing dad. You can love your children and still be a horrible parent. Same how a man could love his wife yet still be a bad husband. Love isn't enough in both cases. He either gets his kid into counseling and make her behave or you need to be gone. If you have any family go stay with them until things improve 

I have 1 question. Did you take the baby to the Doctors?

Oppss. another question. Are you and your boyfriend legally married yet? You referred to him as Significant other (SO) in a Feb 2020 post

You have gotten excellent advice here.  A man who protects one child at the expense of the other - particularly the older versus a helpless infant - is not an "amazing father."  Failing to teach this girl right from wrong is a shocking abdication of parental responsibility.  You are not married yet and have some serious thinking to do.

I get it you are living in an abusive relationship so it's hard to see the forest through the trees, but this man is abusive. Somebody posted on here yesterday a link to a post about miniwives and the destruction it has on relationships. Read that post! Then take a good hard look at what your life is going to be like for the next 10-15-20 years from now.

ETA the link
https://www.steptalk.org/blog/nothanks/daddydaughter-enmeshment-263100

Your DH will belive it when the school or cops call bc she has hurt someone intentionally in school.  She could end up taken and put in a group home and your baby taken bc you can not keep him safe 24/7.

It will not get better, only worse.

I am so angry at your denial to see this "man" for what he is. 

You have a duty to protect your helpless baby.  Even if it means leaving Mr. VERY-Far-From-Amazing. 

As hard as it could be, I would leave 

I've read your previous blogs. Your BF is horrible often times abusive partner, he treats you bad. You already have two kids with him but are not married to him. Now it escalated to your child being abused. Why are you with this  man?? What is it going to take for you to see things clearly? Are you going to continue having kids with him?You and definitely innocent kids deserve better. 

I've had this happen before except it was a head injury and SS was only 6 at the time. I even posted it here for advice and it was a lot like what you got-leave him, never let them be alone together, never let her come over, blah blah blah....

some of these are just unrealistic and a little extreme in my opinion and had I done them I would have ruined my family so I'll tell you what I actually did. I told my DH what happened. I told him that I was worried SS was being encouraged by Bm whether intentional or not because she doesn't monitor how SS plays with her other child and she's extremely jealous of how much time SS spends with my child and not hers. I didn't put the blame on SS because I don't think kids are inherently malicious of siblings unless there's a provoked rivalry. I gave him a chance to help me and it worked out better than I can imagine. He talked with SS about how what he did was not okay, not allowed and will always result in him being punished. He even said "I don't care how you behave at your moms house with Spawn, but not here!" Now I did start watching them closely and gradually I wouldn't check on them as much. They are now 9 and 5 and thick as thieves.
 

Bm sends SS videos of boys wrestling laughing about how much it reminds her of him and spawn....we ended up running into SS with BM and Spawn at the local amusement park that just opened up and SS straight up ignored Spawn to play with BS. BM was pissed because it was 'her time' BUT SS gets to actually enjoy himself with BS because I don't let either one of them get too rough with the other. There are no accidents or outburst when I'm on ''mom' duty. I don't let BS beat up on SS or play like that just like we put a stop to SS acting that way when BS was little. 

Teach your skid the boundary line, point out how other adults handle their feelings of jealousy or rage appropriately (bc it IS normal), keep firm on your consequences when she lashes out and have patience while she is adjusting to new house rules. 

Talking about families and families being ruined...

OP and her two children are also a family. Single mom with kids is still a family. If she breaks up whth her boyfriend, it doesn't mean her family is ruined. Having a man isn't a prerequisite to having a family. Her child gets hurt. Her guy does nothing about it. Which family should she worry about? Family with her kids being endangered or family whth this man who can't care less. 

when I was single raising my DD we were a family. Not having a man doesn't mean I had no family or something was ruined. Safety of innocent children is more important than keeping a man, especially a man who can't care less 

OP, so what will it take for things to change? If you wait until something serious happens you could lose your baby to CPS...