If your 1st bub was also around the 3rd percentile, then it is possibly the same genetic weight for your 2nd bub. My DD was born 75th, but was a slow grower and ended up around the 10th for weight. It is just her metabolism. DS was born around 90th i think, but has slowed to around 50th. i think he will be bigger than DD though, he is just a bigger build.

If your little one is still happy and not losing weight, just keep doing what you are doing. She will start to get in to solids eventually if you just keep offering. Have you tried finger foods?