My cat is well over a year old but is more kitten sized?

She is well over a year old. Her name is Ginger, she s always been small, but our other cat Fluffy is much bigger then her, She s also very nervous and jumpy, though we have had her since 8 weeks old, and she s had nothing to fear. She s grown up with Fluffy and a while back a new dog. She s fine with both, a little nervous around the dog, but she s a collie and has too much energy for anyone.

But i m mainly worried about her size, she s healthy and has been in heat. We got her from a pet shop not knowing what was wrong at the time. (bad breeders).

I wanted to know if she ll grow

Here are some pictures

https://flic.kr/p/G8dRgx

https://flic.kr/p/G88RcW

Self explanatory, Fluffy s the fluffy black and white one, Ginger s the little ginger and white one.