She's ok most of the time. Although we don't always see eye to eye, but she whenever she sees Ds (which is probably a couple of times a month for a few hours) she always mentions about DS staying at hers.
DS is 5 so it's not that he's too little it's just he doesn't want to. I ask him, in a positive way and he doesn't.
She is also almost entirely deaf and I do worry that if DS called out in the night she wouldn't hear him.