2 month old

How many ounces does your 2 month old take, my baby will sometimes do 4 ounces but most of the time she does 3 when I went to the doctor for her shot she asked me how many ounces of milk my baby takes I told her 3 but with more often feedings she said that she should be taken 4-6 but my baby won’t do 4-6 is this normal ?