A is 10.5 months and in 18-24 month vests, and has been for some time now. No doubt she will grow out of them soon. Clothes are generally 12-18 months, and again she has been in these a while. She has worn some 18-24 month clothes too.
She does wear cloth nappies, so her butt is that much bigger so trousers are a real pain, and dont tend to last very long.