Noah'sMummy, I admire your restraint ... I would have told the mum-in-law exactly what I thought, no holds barred!

What kind of an excuse is it that she thought you might keep the kittens. What's so bad about that? It's better than sending them to an uncertain future. She is merely trying to excuse her own shortcomings in the matter, her own laziness. You have every right to be MAD and I do hope you are able to help those poor kitties.