Ehh.. SD being rude and being in her 50's is stupid. I would probably send one more e-mail and say if she doesn't want it you are just going to trash it. I bet that would get a response. 

Once she does respond, kill her with kindness (at least at first).

I'd stop communicating with her since she obviously doesn't want to communicate with you. Everything should go through your DH. If he wants to send her the watch, fine. If he wants to ask her about it, fine. Just step back and let him handle it.

"DH, honey, I just don't know what to do with this watch and family papers. Your Princess didn't respond to me, so I don't know if she wants them or not. Would you just please handle it? Either send them to her, or sell the watch or give it away, I don't care. I just don't feel right about keeping it."

You’re too kind. Pretend you never saw those items.

My SD would continually ignore any text I sent. I'd send a group text to her and her brother inviting them to my house for Father's Day. So my husband would feel special on his day becasue pf course they wouldn't do anything for Father's Day without us paying for it.... She would inevitabley ignore me every time. Then she would show up for the barbeque. GRRRR. I stoppped allowing her to mistreat me years ago. I never communicate with her due to this. Ignoring texts is passive aggressive and I respect myself too much to put myself in that position anymore. Ignore, Ignore. Don't reach out anymore.

She's not going to play nice after all these years. If you don't mind sending it knowing you won't get a response, I'd just send it without further comment. Don't beg her to "let" you do something nice for her. This type loves it when you keep trying because each effort on your part is another chance to reject you.

However, I'd only send it "signature required" because I can almost imagine her coming around in 3 years saying she'd like the watch and acting as if she never received it. It's just a smart move with anything valuable, but especially with someone hostile on the receiving end.

And if you have any notion of getting thanks or that this might win over SD, just don't send anything. You'll be disappointed and it's better to preserve your dignity. Give the stuff to your husband and ask him to dispose of it as he sees fit.

My suggestion is to never care about Skids wants and needs more than their parent.  If DH doesn't care if your SD gets these items then why should you.

It is kind of you to want her to have these items.  I can almost guarantee she is seeing your kindness as weakness. 

I stopped caring about my DH's daughters (I don't call them step kids, ever) about 10 years ago.  My feeling towards them is apathetic.  I wish them no harm but stay away from them.  Just the way I like it.

Tell her you are throwing them out. Stick them in a box in the attic. Bequeath the box in your will. 

Seriously? 50 and she does things like this....I have officially lost hope for my bm now...

Is there still a lot of stuff belonging to SD's mom in your house? If so, why not have it all moved to a storage unit? Pay for the first month's rent, then email this middle aged brat providing details of the location and the amount she'll need to pay monthly.

Be done with her.

Hire someone for the day to help clean out the deceased wife's items. DH can store what he wants in a trunk and donate the rest.  It's not right that you have to tend to the items and are responsbile for getting them to SD. Enough is enough. 

One of my close friends married a widower about 4-5 years after his wife died.  He'd been transferred by his company and moved to a distant city where he met my friend.  When my friend married him she found that his daughters had moved all of their mother's personal possessions like makeup, deoderant, lotion, etc into his new home and populated the bathroom with her personal toiletries.