I think the second last one is the best out of all of them.
In the beginning, your flash is too strong and your losing some detail as well as it seeming a bit soft, in my opinion.
Your second one is nice, but the background is too bright and my eyes are drawn to the sides more than the face.
The third is a lot better with detail kept and it fairly sharp, but your crop is too tight and your colour seems a bit off.
Your fourth is a tad too bright, you need that grass in focus (in my opinion) and the crop is way too tight. We need to see more of her body in that shot.
Your fifth... this is the one I think worked for.
Nice lighting, fairly good DOF, very sharp, and the composition is fine.
Your last one is nice, but once again, the crop is too tight.
I'm thinking for this series that controlling the maount of flash you use as well as knowing composition are where you will need to improve, but these are a good series of images to start with.