Exact thing happened to me and my sister. My mom died at 51, my dad married a few times. His will gave everything to me and my sister upon his death. He got cancer that spread throughout his body and given a few months to live at 79. His wife convinces him to change will to leave everything to her and he does, my sister and I get nothing. It wasn't life changing money, probably only a few hundred thousand but it would have been nice to throw into the kids college fund or pay off my house. The thing that really pissed me off was there were a ton of tools I had bought in my teenage car fixing years that were at his house and I hadn't gotten around to getting. I went to the house a few days after his death and the garage was completely stripped of every tool by my step brothers.
At the funeral my step mom mentioned she'd still like to keep a relationship with my kids, which made me happy as they knew her as their grandmother. My kids went to see her multiple times and after setting up a date and time to meet we'd go to the house and someone I didn't know would answer the door, ask who we were, shut the door in our face, then come back a few minutes later to tell us she was out of town. I hope that cunt is dead and died in a fucking grease fire.