I would give the gift back and then go out and buy myself something that would cheer me up, a replacement gift for a positive feeling.
People can be weird and I don't know how old she is but sometimes you give something away and then miss it. It's hard to explain. For instance, I gave my sil all my kids baby clothes. Not long after I missed them so I asked for one pair of bib overalls back. She thought I was wacky but I was sad and who knew that old clothes would hold any memories for me? She just told me that she's giving away some baby clothes now(it's been years) and she's keeping a few things to remember by. Now she doesn't find what I did years ago so weird
Please don't be hurt by the gesture of your Aunt asking for it back. Probably she feels really awkward herself but definitely go out and get yourself a little something.