Hello Kitty sounds just like my 9 month old Cloud; built wide like a bulldog and she's really put it on since we adopted and she doesn't have to battle 30 other kittens for chow. I call her 'Buddha Belly', LOL.
A bulldog is a great description for how she is built!
That is exactly how Hello Kitty was when we got her. She was teeny tiny then just started eating non-stop. In probably a week to 10 days you couldn't feel her little ribs anymore. When I see pictures of her as a kitten I can't belive that tiny kitten grew into this big cat!