I understand that the front facing ones are suitable from 9kg but I thought the current advice was to keep them rear facing as long as possible, and they're ok until 13kg. However most people I know, with babies the same age as dd, have already moved to front facing.
DD is 11 months and very slightly above average height, and weighs about 20lb. We still put her in her rear facing group 0+ car seat. Her legs hang over the edge but her head does not yet come above the top. However she pulls her upper body forward and away from the head/side cushion mainly to be nosy and I'm concerned that, if we were in a collision. her head and neck would not be protected by the seat at all, of that makes sense?
My concern about the front facing seats is that they would be very upright and she may find it difficult to fall asleep comfortably in them on the rare occasions she does sleep on a car journey
TIA