Child safety bicycle seat advice?

[Saffron]

Any advice on a child safety seat for an adult bicycle? My daughter is 4 but on the 98th centile for height and weight. Looking at the mini seats with just shoulder straps, no sides, I can't help thinking these don't look very safe for such a young child. But are the chair-like seats with high sides going to be too small?

[etta166]

I prefer to use a trailer with my 5 year old, or get him to ride alongside me on the pavement when I'm on the road. I don't think he'd fit any of the standard rear mounted seats and he would probably be too heavy anyway.

[SE22mum]

my nearly five year old still uses a standard back seat. you are welcome to come round and try it out to see if size is ok, before you buy your own.