I’m sorry, this is gonna sound horrible, but if I were you I would have made sure I called a social worker on her and reported her for being mentally unfit to care for herself (even if she is mentally there, she’ll have to deal with it). I would then proceed to tell his parents and family how he is a good for nothing person that will betray them at the drop of a hat and take that evidence with me, turning them against him. I’d make sure life was a living nightmare of inconveniences. It wouldn’t be forever. Just long enough. Something similar happened to me, but yours takes the cake.