She does it because she still just a baby. Yogi had a 2 a.m. wake up call for several weeks. It then moved to 4 a.m., which was fine because that's what time we usually get up. He can now "sleep in" to 6.
Keep your routine with her as consistent as possible and her 'clock' will set to that as she matures. Try to wear her out as much as you can before you head for bed, but really you're just going to have to ride out the baby stage.
Aren't puppies great!
