I haven't been paying real close attention, but I don't think that there's any real difference during the days that she only wakes once as opposed to twice. I usually feed her around 6:30pm, she goes to bed at 7, then she usually wakes sometime between 11-1pm, then sometime again between 4-6am. This has been more the norm than just one feeding. This only happens occasionally. I'm not really sure how to up her intake during the day. She eats about every 4 hours, but sometimes she only makes it to 3 or 31/2 hours. Other than going back to a 3 hour EASY, how do you up their intake when BFing??