Moving a cat from a multi-cat household
I'll try to keep this short!
Almost three years ago, my sister-in-laws (now) ex-girlfriend and I adopted a brother/sister pair of kittens. I got the boy, she got the girl. They were very young and we weren't intending to live together for very long, so separating them didn't seem like a big deal.
About six months ago, I adopted another cat (or rather, she adopted me) and all three cats get along tolerably well. Brother and sister cat are, of course, more affectionate towards each other, but there isn't much in the way of true aggression.
SIL and girlfriend break up, girlfriend now has a place of her own. She absolutely loves her cat, but feels it would be unfair to remove her from her two cat friends. Her place isn't big enough for 2 cats, and that's another factor in her thinking of leaving her kitty with us.
As much as I adore her cat, I can't help but feel overwhelmingly guilty. I insisted if she does end up leaving her with us that she allow me to pay the adoption fees for a used-to-being-solitary cat.
I failed at keeping it short. Okay, my question is this: Would moving this cat away from her cat buddies be that terrible? Is being solitary something a cat can adapt to, even if it has lived with others for it's entire life? What's the best decision to be made?