L.R.
Hi Joylynn,
I was told to NEVER wake a sleeping baby to eat unless they are not gaining weight. If she is gaining weight and seems happy, then I would just feed on demand. My daughter was about 2-3 months old when she started sleeping through the night. She was eating formula AND breastmilk, was gaining weight and was very healthy. Be happy that she is a good sleep right now. I also recommend reading Healthy Sleep Habits, Happy Child by Dr. Marc Weissbluth for age appropriate sleep needs and cycles.
Sincerely,
L.