how much formula?

Brittany
So our sitter is awesome but she told hubs our almost 12 week daughter is eating between 6-8oz each feeding. I was shocked because at home she only eats between 3-4oz at each feeding with us. During the weekends we mainly just breastfeed as often as she wants so I don't really keep track...in the morning and before bed she gets between 2-ounces of formula though. Anyway so my question is, how much are your 12 week olds eating? Does 6-8ounces seem too much?