DD was on the late side, at around 3.5yrs. We'd tried earlier and it was a disaster.
She got wee really quickly, had accidents here and there but mostly went to the toilet. Poo was another story. I was determined not to go back to nappies so we stuck it out. It took well over 6 months for her to really 'get' poo. For some reason she just did not want to poo in the toilet. It was very frustrating and annoying cleaning poopy pants all the time, but after she turned 4 it just clicked. Now I can finally consider her toilet trained! I did a poo chart on the fridge, she got a stamp every time she did a poo in the toilet or potty and after a certain amount of stamps she got a 'prize'. The prize (a new book or toy) was in sight but out of reach. I think this really helped incentivize her but it wouldn't have worked before age 3.