My son ate every hour or two until he was almost 3 months old. I nursed until 5 months, so not sure on the amount, but he was constantly hungry. It was like he was always on a growth spurt. But, in his case, it was normal and healthy. He too would spit up a tonne, but didn't have reflux..he was just a hungry little bear..lol. Eventually he slowed down...and mommy got some sleep..lol. Just a different type of situation. I would most definately mention it to his Dr.
Babies love to suck and can take more from a bottle than they need because they like to suck and the milk comes out so easy. 3oz is a normal intake for that age, but every baby is different. Have you tried giving her a pacifier after 3 ounces or after the 1st bottle. It is also possible that she has reflux. Babies can confuse stomach pains for hunger. Does she spit up a lot, squirm when eating, arch her back often, get fussy - especially in the evening, or drool a lot? If she has reflux, then you should talk to her pediatrician. My son started on zantac at 8 weeks and it really helped his reflux.