CB, your mom needs to make friends of her own and join fun groups or a church or anything and not make YOUR kids her life. I don't know how open she'd be to hearing that, but I'd probably tell her that once.
Because of how medley she is, I'd keep stuff about my kids to myself. She's not the mother and grandmothers aren't normally invited to IEPs. I'd try to keep her out of the know.