DS1 - tried to give it up at 2yr2months when DD was born, but still had one every second day given the *right* environment (he was full from lunch, nice and warm with a blanket etc and gee whiz, he went to sleep ) - entirely at around 3yo

DD - stubborn little minx gave up day sleeps by 2yo - and night sleep for that matter - but that is another story

Go with the flow - even if it means a sleep every second or third day - but a rest is still important IMO