1 1/2 Year Old Is Sleeping like an Infant Again.

I actually think putting her to bed EARLIER not later might help. It was the craziest thing with my younger daughter, but if we put her to bed at 8:30pm she'd be up at 6am. If we put her to bed at 7:30pm she's be up at 7am. I'm pretty sure there is a reason for this (I just don't know what it is). Maybe it has to do with how your body cycles through the sleep stages. If she comes to a more wakeful stage at, say, 4am, then she'll probably go back into deeper sleep for another couple of hours. Versus if she comes to that more wakeful stage at 5am, well, then she feels like it's time to get up! I don't know. Worth a try right? Good luck. I hated all that sleep stuff when mine were little!! So hard :(

Not knowing your schedule, can you put her down a bit later in the evening? That may help her sleep longer.

My child did this when he was going through a growth spurt.
I didn't realize it until after the fact when I could see the actual difference
on the chart either at doctor appts or at home on our wall chart.
He went through several of these changes and eventually it all leveled off.
But you might have another 6 months or so.
Hang in there & try to go w/your baby's flow. It will make things easier &
it will change.
Also, be prepared for another change or two in your baby's development.
It changes.
Rest when you can! Even if you can't sleep. Lay down & rest!
This stage too shall pass. Hugs.

Maybe the early morning light is waking her up? Try some heavy shades to keep her room darker. My youngest is, as my pediatrician put it, "light activated" so we are all up very early during the summer months!

I agree with Malia.. Also make sure this child is getting a lot of active play during the day.. Outside for at least an hour hour and half is best in the morning and again in the afternoon..

Could be she is going through a growing spurt and is needing a little more sleep, but you need to help her adjust to the once a day nap by adjusting bedtime.

Do you think her molars are coming in?

Are there any disruptions that are occurring at 5am (birds singing, too much light in bedroom, too cold?)

My son has a time in the early AM when he starts to wake and if there is a disruption, he will become fully awake instead of returning to sleep.

I discovered once that his night light had blown out and that was causing him to wake. That is to say the change from a completely dark room to a room with a bit of sun disrupted his sleep.

I agree with the idea of trying an earlier bedtime. I have heard that it is good to adjust 15 minutes at a time.

When is her bedtime? Keep her up later so she'll sleep later.