My MIL supposedly has multiple personality disorder. She is on no medication and receives no therapy for this condition. IMO, this would make her a little unstable. Even if she doesn't really have it, I would still consider her unstable (maybe even more so) for thinking/telling people she has it. Either way, I would rather she not be solely responsible for my son overnight, especially when she lives over an hour away and is 63 years old.
What do you guys think?