If it helps at all, Pumpkin, I've found that most cats won't get along right off the bat, but given time, they learn to if not like each other, then at least live with each other. My mum's stroppy fluffbag was *most* upset to have two strange kitties in *his* house when we moved in, but after a few weeks he settled down and they all learned to just tolerate each others' prescence... and when we moved into this house, Mr Ginger was pretty p-o'd that there were two dopey new tabbies he was expected to share with, but now they're all best mates. And after seeing Mash learn to get along with our cats, mum ended up getting a Siamese and they've now learned to be housemates, if not BFFs... is there a way your MIL would be willing to put up with a couple of weeks of kitty-spats until they all settle in together, or is she dead-set against upsetting her baby by introducing it to yours? I really hope you guys can work it out!!