Hi M.,
I am going through a change with my almost 3 year old daughter. The only difference is that I took her pacifier away about a week ago and since then she won't nap during the day. She used to take 3 hour naps and still go to bed at 8:30p and wake up at 7am. It was VERY difficult, and still is. What I started to do is after lunch, I do our bedtime routine, brush teeth, read story, sing song and lay with her for a little while. Then I explain to her that it's quiet time and she can't get out of bed until I come to get her. I leave 2 or 3 bookd for her to "read" and she'll read to her kitty or her doll. Quiet time is 2 hours and usually after an hour or so, she starts her screaming. Usually I let her do it for about 15 minutes and then I go up there and explain it's still quiet time and if I can hear you downstairs then you're not being quiet. I leave, and don't go back up there until it's time. Usually she falls asleep. It starts at 2p and she'll literally fall asleep at 3:30p.....but at least she's sleeping.
That's what has worked for me and my daughter. It's difficult and very trying, especially b/c I have a 5 month old that is constantly woken up by her, but we're getting through it.
I hope you find a solution. Good luck! :~)
K.