I stopped naps with my youngest at 18 months because she was up until 11pm or 12am if she napped...even if she just fell asleep in the car. Even with a nap, she would sing to herself until 10pm most nights. She always woke with the sun at that age, too. She seemed to just need less sleep than the rest of us.

She is 10yo now and still is a night owl but she will sleep until 8am or so most days.