That's kinda asshole to fight over what you're going to get for inheritance from a parent who is still alive.
I'd be trying to find a way to trade everything I own material wise to have my adoptive parents forever.
Usually what happens is you end up with nothing because the relative leaves and material items are subject to decay and whither away.
I have a friend who inherited her grandma's house, only to find the house was rotted, got condemned and razed at the expense of my friend.