4oz of formula?

Maria • Sept29💗
My 6 day old baby sometimes drinks close to 4oz of formula.. I feel like that's way too much for her to handle 😟 she spits up maybe 2/3 times every feeding.. am I over feeding her? 😭 FTM & im trying to figure this out.. doctor told me to give her as much as she wants but isn't her stomach the size of a marble rn?:(