I have 3, one is a year old and fairly small, the other 2 are about 18 months and are quite a bit bigger, the boy 18month old one seems to have grown recently and when he stands next to Moritz (the year old) he dwarfs him!
So i just wondered wether my imagination is playing tricks on me and Max has not really grown and wether Moritz will get any bigger. Mirella has grown since she had the kittens but then she had a bad life before we met so i would expect her to