I had a car accident last week and DD's car seat was damaged. She is 14.7 KG. I don't really want to buy her another car seat which relies on its own straps to restrain the child, as I've always been slightly unhappy about whether I've fixed it properly - it's a relief that DS is older and uses a seat which uses the car seat belt. But most of those seem to be for children over 15KG. Are there any for lighter children?