Hi Sarah!
Welcome back. I've also got a little girl who is 15 and a half months, she is 21lbs, not so much more than Hollie! If she's very energetic, she must be burning up her calories - lovely to have such an active little lady! (exhasting though...
) I don't tend to take to much notice of clothing sizes, they vary so much, Sainsbury's babygros seem to be made for baby giraffes