my son was born 3 days after your daughter and hes the same. hes only had 5oz a hand full of times and sometimes doesnt even finish his 4oz! i just give it to him when he wants it. if he doesnt want a full feed then i just wait until he wants the rest and give it to him then. hes also gaining fine, i think every baby is different and aslong as they are gaining and having lots of wet nappies theres nothing to worry about. i bf for the first 8 weeks but then switched to formula due to him falling asleep on the breast really quickly and not getting enough. although its nice to know how much hes getting with formula, the guidelines on the back for the amounts they should get are annoying..hes never had the right amount and i really worried about it when i first started giving it to him but he seems happy enough!lol. will be interesting to see how much the other 12 weekers eat!x