M.R.
For information based upon infant sleep cycles and patterns, you may wish to read the book "Healthy Sleep Habits, Happy Child" by Dr. Marc Weissbluth. He is a Chicago-based pediatrician who specializes in infant/child sleep issues with over 30 years of research in the field. You might find the information regarding sleep patterns, circadian rhythms, the 'early wake' you mention, and 'prime time' rather interesting. It would definitely shed some light as to why your child is doing what she is doing.