Expressing is not a great way to judge your supply, unfortunately! Pumps are no where as good as a nursing baby at extracting milk, although some of the electric ones come close. You said she's gaining weight well - how much? And how many wet and dirty diapers does she have? That and having a baby with nice alert and active periods are better judges of your supply. Also, pumping in the evening, even if it's from the other side, will be a lot less than pumping in the morning, as your milk supply tends to drop during the day. Have you ever tried pumping after her morning feed?
