My daughter is 12 weeks old and I'm trying to determine when her wakeup time is in actuality.

I would like to say that her wake up time is between 6-8am but whenever she wakes up during this period, she gets her diaper changed, eats, and then immediately falls back asleep for a good 2-3 hours. This makes me wonder if her real wakeup time is between 9-11am.

Her pattern, these days, looks like this:

Long sleep: 11pm-4am
4am wake up, diaper change, feed back to sleep
6am: wake up, fuss on and off until 7:30-8am
8am: diaper change, feed, falls asleep
10-11am: wake up.

Thoughts?