Is she starting reception so will be 4? I wouldn’t go for playsuits as they’re going to be tricky for a last minute rush to the loo, especially with a jumper or cardigan on top.
Both of my girls had polo shirts, Asda used to do lovely soft feeling ones and easy pull on skirts or pinafores, the jersey ones with no zips or buttons.
I got them both trousers too, especially for the winter when getting tights on and off for PE was still a bit too tricky.