My 7 year old dd is 136cm tall, not sure of weight but probably about average for her height. Do I still need a hbb for her? Or a car seat at all? I'm pretty safety concious with car seats, all three dcs have been in extended rear facing seats etc, but my very large car is coming to the end of its life and since I hardly use it anymore, I'd like something smaller...much easier with only two car seats to fit! Currently have 2 hbb and a kiddy guardian pro with impact sheild.