My children are both like this. Our daughter will be three in October and our son is almost 6. Ours won't sleep in if they stay up late either, they still wake at the crack of dawn. Then they are just a cranky mess all day. I have yet to find any solutions that work that great. I know we used the time change to help train our kids to "sleep in" until 6:30. We would let them get up for a few minutes and show them it was still nighttime (Because it was dark out) and not time to get up. A few minutes of cuddles and back into their crib they went. That usually convinced them to stay in bed a little longer without the screaming. In their little brains they thought they just woke up in the middle of the night. Now that they are both in big kid beds, I have trained them to come in to get me when they wake up. Then we can "cuddle" for a while. Which, I admit, often means I turn on cartoons and doze if they are up before 6:00 or so. My SIL had great success with the alarms that you can set with red and green lights. She sets the time. If the clock turns green, her daughter can get out of bed. If it's red she has to stay in bed (or her bedroom now that she is older). She started this right after her daughter turned 2 and really knew her colors well. (We tried this with my son, he's not a big a rule follower as his cousin. He kept coming in and announcing what color his clock was to us). The down side it that she has accidentally trained her daughter to sleep in until 8 or 8:30 and waking her up earlier is a complete nightmare. She is VERY concerned about starting a kindergarten school schedule here in a few weeks. So it may not be all bad.