The lighting is pretty good overall; even and with large highlights in the eyes. The little girl's dark hair could maybe use a little more light (judging by how it looks on my monitor), and in the 1st one it looks to me like she may be squinting a little, which is a common issue in outdoor portraits.
#1: I always like to have something besides just the face - ie. get her hands in the photo, or an appropriate prop (like a flower, or a hat matching the dress)
#2: Good job! Nothing needs to be changed, except maybe more light on the little girl's hair and the dark area between them. They have natural expressions, and the eyes are both looking at the viewer.
#3: In my opinion the girl's cute expression and pose, make any technical issues irrelevant! (The technical issues would be, again the hair is slightly too dark, and the finger out-of-focus.)