feeding

How much do your LOs eat? My little girl is only a week old today and we are trying to breastfeed exclusively, but I was told to use formula to supplement. We have cut back on formula significantly, but I'm still worried I'm not making enough/she's not eating enough. I decided to pump to see if I could keep track of how much she is eating and today with her first bottle, she ate less than 2 ounces. Probably 1.5-1.75oz. Is this normal? I've read online that babies should be eating anywhere from 2-3oz a feeding, and around 25oz a day. Her pediatrician wants me to continue to supplement but my LO does not want any/refuses and when she does eat it, she spits it up... today she even spit up hours after! Blah this Mom stuff is tricky ;)