I started school at 4 yrs old in the 1950s because of where my Birthday fell. I played catch up for the rest of my school years and really struggled, however I was toilet trained, was able to do up and take off my own clothing, I couldn’t read or write though, but I could knit and sew! Shows what my mother thought were the skills I needed! By then my Mum was severely depressed, so I was left to sit by her side most days and she knitted and sewed, if I tried to read anything she would rant and rave at me. Anyway .
Our girls were aged 5 and could read basic words, could write, draw, definitely toilet trained and could whip off their clothes as soon as the sun came out ( we had to tell them about not doing that in school!)
GCs, again started school aged 5 and could read and write, draw and do pretty much everything. By then laces had been replaced by Velcro fastenings. They threw themselves into Ballet and school activities at a very young age.