we used to have a pet chameleon that we let run loose around the house, one day when my mom had poured liquid glass into a tray he snuck in the room. As the liquid glass was drying he slowly walked over the surface and became stuck in the hardening glass. I was reminded of this because every tray my mom has made has cat hair mixed into the liquid glass
you could make a quilt like tree, like this http://www.craftster.org/forum/index.php?topic=211628.0 since a quilt is kinda like a family thing, you could even applique the tree on to make more definition. Can it be 3d, because you could for a small tree out of wire or real tree branches and hang little things that remind you of each family member on the branches.
if its felt to leather it seems that tacky glue would hold for a little while, if you really want it to stick there is a leather glue called barg's that is a red and yellow tube, i think, with a bear on it. that works for all leather crafts