my son is 3 in may and is finally out of nappies in the day. i remember asking the same question on here a few months ago and people said he will do it when he is ready and it worked, he is now dry all day. i tried to make it a fun thing, he liked to put something in the bottom of the potty and found it amusing when he weed on it, just a bit of paper or a sticker or summat.
the worst thing to do is keep putting her back in nappies, i did this for a while but it kust confused him. i woke up one morning with the determination to be patient. i stopped putting nappies on him and let him run about with nothing on his bum in the house and when he weed on the floor i just placed him on his potty and asked him to stay there for a couple of minutes, i didnt shout but made him aware it was naughty. after 3 days he was doing it him self, then two weeks later we could go out without his nappies. try not to go out to far for the first weeek or so. my son still says he dont need a wee but when i take him toilet he does it. try to make it into a game for him, try a sticker chart or a special treat box, when he uses the potty let him have something out the box.
every child is different