You don't sound crazy at all! People really are not always what they make themselves to be, and it's not necessarily easy to tell what they're hiding, or know what games they're playing. If she was as toxic as you've suggested, it's very chilling, and typical that she would run a bereavement support group, taking charge of people who are at their most vulnerable.
I bet you aren't the only one with confused feelings about her death. It's very difficult to talk about stuff that dark and confusing!