Kitten head size question

Hello,

well, Lola is 4 and 1/2 months old now and has grown considerable since I got her in early November...however, her head still seems small in comparison to her body. Her body is not fat...normal kitten shape. She's a normal, clever kitten, except for some ongoing gastrointestinal issues. My parents have a cat that has a tiny head and a big body (head would be small for the body even if she weren't a bit overweight), and she's still smart. Does anyone have a cat like this? Sammy is her brother from an earlier litter and his head is in proportion to his body. Is it just a genetic thing, or could it be because she was sick early on (feline distemper at 5 weeks)? .

I think it's just genetics. Our cat and his four siblings all have small heads, and three of them have rather large bodies. They're not well-proportioned, but very intelligent, judging by the way they get into things.