Yes. Why would you hang on to stuff you can't use? Give them to her or you will seem really petty and unpleasant and I'm sure you want to have a good relationship with her.
Yes - they belong to the baby, so please give them back to your soon-to-be ex d.i.l. Divorce is always sad. I hope you manage to maintain a reasonably good relationship with her , for the sake of the baby. Good luck to all...
Yes unless there are other babies in the family you might need them for, in which case have a chat with your son and ask if you can keep a few things at your place for baby visits. Nothing should be kept without their agreement though.
My son and dil are getting divorced and today I received a message from her asking for all the baby stuff I have stored in my loft as they did not enough space, some of this things I bought for them, should I give them to her.