My daughter was the same, she was on 4 oz at 2 weeks cause she was constantly hungry, if she's hungry then feed her. It's all trial and error when it comes to your first baby x
My doctor told me that babies stop eating when thy are full. My son ate 4oz from about 2 weeks till he was 6 weeks.
My son would eat 3-4 ounces, if she's hungry let her eat. Or try burping her to see if that will help, if it didn't let her eat (= my sons doc told me not to, but my son was hungry so I fed my son.