Aw, normal lang yan sa 18 days old, lumalaki ang appetite nila super fast at baka talaga kulang ang 2oz para sa kanya! A few of us tried increasing to 2.5-3oz at 3-4 hour intervals, at honestly okay lang yan, babies won't overeat kung formula lang ang binibigay, kaya if she finishes the bottle at gusto pa, try mo mag-offer ng 3oz at i-observe mo lang kung paano siya umuubo after. But best to check with your pedia kung okay ba ang weight gain at feeding pattern niya, especially since she's still very new, they can give you specific guidance based sa baby mo.