What was up with this girl?

So this guy I know well I always talk to him on facebook and I commented on some of his pics one was something like awww cutee is that your little brother? And then she comments on the same pic awwweeee your little brother!!!! :D then I said on another pic I love your dorky smile (we always talk about our dorky smiles) and she then later comments awee I love your smile!!! :) why is she doing this?