#1 has some colour balance issues. She is very yellow in the picture. Not sure I'm liking the angle either. Nice choice of location though
#2 nice concept, but the picture seems to lack focus on the eyes and her face is a bit under exposed. There is also some empty space above her head. Another good location choice.
#3 I like this one. Clean and sharp image, subject filling the frame nicely. Not liking her expression in it though.
#4 Probably the best in the series, clean picture. Nice framing too.
As stated, she needs to have different facial features going on. She is a pretty girl, would love to see her smile more.