Oy... PPD is no joke and her trapping herself in her room and ignoring the baby are signs of that. Since she is not a minor, there is not too much you can do unfortunately. Thank goodness you guys are helping the baby. 

I am so sorry you have to deal with this. What is your wife's plan? How long is she willing to let this behavior happen?

Not good.  The longer your wife spends being the primary care giver to the baby, the more she will bond with it.  It is a primal thing that simply can't be helped.  Once that attachment happens, your SD will have the ultimate blackmail card forever.  "Kick me out and you will never see the baby again."  For everyone's sake, anything short of a herd of elephants and dynamite has to be used to get that girl out of her bedroom and taking care of her own baby or you may as well accept that the child will get her high school diploma still living in your home.

I love the way she calls herself a 'single mother'.. enjoying all the martyrdom that comes with that loaded phrase but experiencing none of the actual work or consequences. Your wife is actually the only mother in that equation.

 WHY did you and your wife agreed to this arrangement? Rhetorical question.

Families may be  complicated but,  tried and true most are generational by nature. Was your wife a young unwed mother? Maybe granny was?

No way,,,no way NO WAY am I or my husband gonig to raise one of our kids INFANTS or children. We have had this conversation a long time ago. We also occasionally bring it up again JUST in case one of us has changed their mind. But oh nooooooooooo. Not going to happen.

Doesn't matter what the circumstance may be. We discussed it all and always came back to NOPE. That include if for gosh sake one of our children lands in jail as a parent.

Time for you and your wife to sit down and discuss YOUR HOPE'S and dreams as a married couple, 1 year, 3 years 10 years from now. Hopefully you both will be well enough to experience all the big and small dreams you have.

I do not believe your hope and dreams with your wife included raising your adult daughter and step grandchild.

Get sd treated for Baby Blues,,,call her OB/GYN today or tomorrow. She needs to take care of her own child in her own place. wouldn hurt to have bio dad to baby chime in too. He may be more willing than SD wants you to think.

Good Luck

Your SD is not a single mom -- she has you and your wife doing everything and more than a husband would!

Your SD has no responsibilities, so it's not too much to ask her to deal with her kid. If she cries that "single mom" BS, she should be reminded she has no responsibilities that real single moms have. If you weren't there, she'd have to deal somehow, so make her deal.

It sounds as if she knows all the plays in the book. I'd be depressed too if I were in her position, that's why I didn't have kids I didn't want. Remind her this was her choice and she has plenty of help, but she must bond with her baby and learn to be a mother, in spite of being depressed. When she has trouble coping, she might seek help herself, but as long as you pick up the slack, why would she seek help?

Tell your wife to stop doing for the baby. It's not helping anyone.

I'm not buying it.. My guess is that this is a woman who has been pamperred her whole life, made a bad decision and now doesn't know how to 'adult' as they say. The best thing you can do is allow your SD the gift of lying in the bed she made so she learns the severity of the consequences of her actions. If having a baby is so easily pawned off on her mom and it gives her this power over you wife, what is to stop her from having another child? Why not, you get to be the social media mom, have all the acolades, all that power over grandma and yet NONE of the responsibilities. Tell you wife that she is robbing her daughter of important life lessons.

What did she think was going to happen after the baby came?   That she would land a 'reality tv' show, get pampered and have a cute little dolly to show off?   

Yeah, truth hurts.  It's only been one month, she's hormonal.   DW should go with her to her 6 wk post partum check up and talk to the Dr,   

Insanity is doing the same things over and over again while expecting a different result.  You let her back in.  That was insane.

So, do something different.    Call CPS, get her in the system, get her registered with the appropriate support agencies and get her ass out of your house.

NOW!!!

I am a man. I get that I don't get it. It being the whole post partum thing.  Not only am I a man, I am a non breeder so not only do I not get the PPD thing, I have never experienced it second hand with a partner who recently had a child.

That said, and I know I may get blasted for this, people have been having spawn since the dawn of man-kind.  Even today in many locations of the world women drop a kid, swaddle the baby on their backs, and go back to the rice paddy, field, work shop, etc....

When failed waste of skin people play some lame excuse for their continued chosen waste of skin failure status by playing a bullshit excuse it needs to be highlighted and they need to have their noses firmly scrubbed into that stinky spot in their life's carpet.

Start rubbing her nose it and quit facilitating her chosen failures.

IMHO of course.
Congratulations Grandpa.

Good luck.