why not give them to charity and forego the tax receipt, no one says you have to claim it as a charitable donation, you can just give them away.
Just an idea, less work, seriously it's her clothes, if she didn't care enough to do it, I don't know why you have to care about them, it really doesn't make sense.
You could also just throw them in a firepit and burn them, that might be fun too.
Seriously so many things to do, wasting your precious time itemizing clothing that she is giving away to charity seems like such a waste.
Drop off the box at her place if you can't burn them, give them away or throw them out.
Leave a note that says "Hey you forgot to itemize these, they weren't included in the tax return" and leave it at that.
