Infant big appetite

Hi I am a FTM here and have a 3 weeks old infant. I feed my bb on demand and realized her appetite have increased from 90ml to 100ml. (If I stick to 90ml, she still demand for more so i increased to 100ml and she can finish it and fall aslp again) I am kinda shocked for a 3 weeks old bb to drink so much. Please advise if this is the normal intake for 3 weeks old bb? What is the avg guideline? #advicepls #firsttiimemom