Good Night Sleeper but Bad Napper

My 9-month-old daughter sleeps through the night and has been for nearly 7 months. She goes to bed between 6 and 6:30 and wakes up in the 4:00 a.m. hour. She babbles for awhile and then I usually don't hear anything more until 5:20am. I am not sure if she is going back to sleep or just playing during that time. Once she starts "complaining" at 5:20, I go in to get her.

She is taking 2 naps and they are usually 30 minutes long. Based on everything I've read/heard, she needs more than 12 hours of sleep a day at this age. She is usually in a good mood but gets tougher as the day goes on -- and I think it's because she is tired from lack of napping. Also, she usually is crying when she wakes up from her naps. We have tried to let her cry it out when she wakes up after 30 minutes but she gets more and more worked up and doesn't fall back asleep.

I have read several sleep books and am using Healthy Sleep Habits. That is what we used to train her to nap in the first place starting at around 5 months. She took 3 naps until recently and we just put her down around 2-2.5 hours after her last awakening. At 8 months, she no longer would sleep for the third nap and just cried and cried so we went to 2 naps. Since she doesn't display any obvious sleep cues (i.e. rubbing eyes, losing interest in toys, etc.) it's hard to determine when it best to put her down.

Based on Weissbluth's optimum sleep time advice, I am trying to put her down at 9am and 1pm. Since her naps are so short, I went back to putting her down between 7:30 and 8am for her first nap (between 2 and 2.5 hours after she gets up) but that has failed miserably. She cries and cries and gets so worked up and can't calm down.

Should I go back to 3 naps even though it appears that babies her age should be down to 2 naps a day? I am thinking that if I could make her wake time later (i.e. 6 or 6:30 am), then maybe the napping would follow. Any advice on doing that? She is already going to bed so early.

I know I should be glad that she sleeps 11 hours at night but the inability to plan around naps is really stressing me out plus I worry about her not getting enough sleep. Thanks for any help you can provide.