Hi, I've asked so many people about car seats and I'm constantly being told different advice, I know they say to keep them rear facing as long as possible but then I've been told it goes on their height, was then told it goes on weight then was told that back along A law was passed that said that no matter their weight or height they had to be rear facing till 15 months. My LG is Extremely tall so she went forward facing at 12 months, but my son who's 14 months is smaller than she was so is OK rear facing at mo. The plan is to give my son my daughters car seat and get my daughter the next size up. I was told that when her head is above the back of the seat then she can have a new one, she's 3 and I'm not even sure that's the correct advice