#1 is flat, the background is terrible, and why are you shooting her from above?! Down low, show us the legs.
#2 is potentially nice, but comes across flat and cool. Not sure about the cropped hat. She's quite good in it, the photo isn't all that.
#3 is getting better, I'd lighten and warm her up a trifle. Also the farmer's tan visible on her arms is not so hot. If she wants to be a model she needs to start paying serious attention to stuff like that.
#4 is lovely. See how warm the light is, and how the shadows reveal the shapes so well? Nice.
#5 is ok, I don't get the shoes with the outfit, though, and she needs to work on her posing. If she's comfortable, the pose is probably no good. She should spend some time looking at fashion magazines -- muscles are engaged, there's a lot of twisting, stretching, tension in the body.
#6 is also nice to look at, but I don't like the lighting. Dead-on lighting is actually kind of a fashion trope these days, but they're going for either a paparazzi feel or a facebook feel, so the poses have to be quite a bit different and the light much brighter to pull that look off.