First of all, way to go on getting her onto a schedule. Great job! I have a 3 year old and a 9 month old. My 3 year old always starts to wake earlier this time of year when it's getting light earlier. We usually put on the blackout shades from Home Depot and that works. I did buy some blackout curtains for my 9 month old and those work, too, to keep it dark. Since babies really are wired to sleep around 11 hours at night, you are right that she really should be able to go back to sleep for another hour. I would just say to keep it dark and to let her hang out in her crib for a while. My daughter will go back to sleep after nursing at 4 or 5 am but some days she takes a little longer. I used to have a mobile and that worked great to coax her back to sleep. Do you have one? If not, I might suggest buying something that can go inside her crib that maybe has lights and soft music. Since the mobile should come down around 5 months (because of possibly starting to pull up), I would not spend the $ on it. They have some cute crib toys at Target for about $30. I, too, have the book Healthy Sleep Habits Happy Child (love, love it) and the earlier bedtime might work- maybe 6 or 6:30. If you read the book, the later bedtime idea seems correct but actually makes the kids overtired and backfires over time. Good luck and again, great job!