Basically what it says in the title. My daughter is one week old today and has been on 3oz for the past few days but today has been guzzling down her bottle no problem and wanting her next bottle a lot sooner than we normally give it to her (every 3 hours). It seems she's spent the day with a bottle in her mouth. Is it too soon for her to be on 4oz? I don't want to over feed her and create a little ball baby or to upset her tummy but it seems like a bigger bottle is what she's asking for