If she's so tired... Why is she waking so early?

This is driving me nuts! The last two mornings Grace has gotten up at 6:15 or earlier (today was 5:15). Then she's awesome for daddy until 7 when he has to start getting ready for work. As soon as I get her she is cranksville and whiny. Then when Kris leaves at 7:30 she is miserable. Now it's 8:30 and she supposed to be eating breakfast. What's she doing instead? Fall asleep in her highchair and she can't even stay awake to finish her formula.

She is clearly exhausted. She's averaging 8 or 9hrs of sleep at night. I believe 99% of her crankiness in the morning is due to being tired but I can't get her to sleep longer. I've tried putting her to bed earlier and that doesn't work either. She does STTN but since we sleep trained her using the Baby Whisperer method she's been waking earlier and earlier. 5:15 is just way too early in my book! Kris tried for 45 minutes to get her back to sleep this morning but it didn't work.

Is this another stage that they grow out of or will she always wake this early? I'm not a fan of anything earlier than 7... It's killing me!