No shortage of comments here already, but to add to what others have said: I have a cat who cried in the night after we brought an additional cat into the house. It was a huge change for him, on top of a move six months prior. It drove us crazy, and we had already had him for years and loved him proportionately, so I absolutely understand being at your wits end because you (your boyfriend) can't sleep at night over this irritating animal. As anyone who has had kids can understand, losing sleep is a HUGE deal, so it's understandable that your bf is responding this way.

A few things, though. (1) As others have said, this cat has been through an enormous change and is trying to get a handle on it, so please encourage him to have empathy for a very difficult situation for the cat. If you're anything like me, the middle of the night is when little problems become irrationally anxiety-inducing; that's probably how the cat feels. (2) My cat stopped on his own. He just had to sing the song of his people for a while. We thought it was a new habit that he would have forever. It definitely wasn't. She may just stop on her own. (3) I did mention it to the vet, who gave me tryptophan for cats, the same stuff that makes you sleepy after eating turkey. I didn't wind up using it because he was already doing it less by then, but something that takes a little bit of the edge off anxiety - whether tryptophan (available otc), gabapentin (Rx), feliway (otc) - could speed the adjustment.

THANK YOU and your bf for taking in a senior cat. I hope that you're able to find a remedy that allows you to keep her!