One kitten is never enough. But there is something to be said about spacing them out a bit - at one time my exgf and I had 6 cats all about the same age - when they started turning 19 - 20 yrs old we had something like a cat black plague and they all died within about a year - it was horrible (I mean they were old and had good lives - but just as we would start getting over 1 - another one would go - also now if my backyard is ever dug up - it will appear as though we were some weird cat worshipping cult or something)