T.S.
girl you have to play play and play and tire the hell out of them. I have a 14 month girl and she gets up about 8:30 sometimes 10:00 - and I play and play and somewhere between 12 and 2 she is tired and ready for a nap
I lay her in her crib put on her nightlight and some ocean wave sounds and leave her there. eventually she will fall asleep. she will sleep until 4 pm maybe and then we try and keep her up until about 8 pm then its bedtime.
taking them outside and letting them run around helps us out too.
hope this help - good luck!!!!!!!!!!!!