I'm hoping my mother will finally give me the engagement ring that my aunt left me. (I wanted to use it as mine, but drama), and the best gift she's giving me is staying home. (even more drama)
I've heard a couple of different stories from my mom that her mom gave her a necklace that was pasted down generations for her wedding day. (it was her something borrowed, as it belonged to my aunt)
I think a sentimental gift might depend on your relationship with your mom and family traditions.