Wow...sounds like he's really angry at your mom for killing herself. Maybe he has these thoughts too, but like you, he can shut them out. Maybe he doesn't understand why she couldn't do that. I wish my brother and dad would get help. They suffer so much but wont recognize something is wrong. I'm sure my brother will end up in jail or dead due to drunk driving one day. But I've done all I can do with them. Hopefully, your brother's anger will subside one day. It's not healthy in many ways for these girls not to know. But I know you know that. I'm sorry you feel bad. You can't control it, so you have to let it go. Maybe you can keep up many pictures in your home, so they'll ask one day. =) Then she'll come back to life.