I think my mom pawned a family heir, what should I do?

You may want to consider that mom may not have wanted to pawn it. She may have needed to pawn it. All family heirlooms are not always meant to be kept. My great grandmother ped on a ruby necklace for those just in cases. It was stated that nothing is worth more than our survival... Maybe this is what your mom may have used it for. Keep in mind when things are tough mom will not always reveal this to you, in hopes of allowing you to enjoy your youth. Don't hound her, consider all aspects. Peace and Love.