8 day old eating too much??

I know everyone says she'll let me know when shes hungry and to feed her whenever she gives me the signs but tonight she has been eating like crazy! She was doing good all day. Drinking between 2-3 ounces and sleeping for 2-4 hours. Then this evening she has gone from eating a 3oz bottle then would be hungry 30-45 mins later and would eat 1-1 1/2oz. Then she'd fall asleep for about 45 mins to an hour, then wake up and eat another full 3oz bottle! It's been going on like this since about 6pm tonight.

Is she eating too much or is this normal? I dont remember my first ever being this hungry in such short amounts of time..