Looking at her gains at week 2 and 4, they are certainly within the normal range for a newborn. And bf babies tend to really plateau from about 3 months. So I don't think the weight gains are too much of a problem. And it's good that the nappies sound right etc. Where is she on the charts btw? Also are you seeing a MCHN or GP and have they expressed concern? What does your instinct tell you?

I have a 2 1/2 year old who was in the 10th percentile for a quite a while, yet he was a huge eater. I think some babies are just small. If you have a worried health professional or you feel like something is wrong, then I would suggest seeking medical advice (or a second opinion) just to rule out a problem. But otherwise it sounds to me like your DD is doing fine.

If you do want to try and help her gain more, from the advice that you have received, feeding more often is the most likely to help. But if she is already feeding as often as she wants then that is difficult. You could try a dream feed if you don't already as a way of squeezing an extra one in.

It does sound like you are doing a great job though.