Check with local costume shops and community theaters . . . they might want Mom's dress.
They might indeed use it. I don't know what's best, to store it, or to give it to someone who will say "This is really neat".
Mom's dress is home-made, she made it herself, and it isn't fancy either, but it does have elegant tiny buttons on the sleeves and is all lace with satin underneath.
One of my cousins wore my granmother's wedding dress at their 50th wedding anniversary party. There are possibly neat uses for yours yet to come in the family, with daughters and grand-daughters around. I am not sure I will have that :~D