They're a good set of images, but you need to consider a couple of things in each image for taking them to the next level (you've had all the compliments, so this is now down to business to help you improve).
Firstly in #1, either scalp or include more of the top of head, but avoid doing the crop at the hair line as this leaves the image looking like you made a mistake with the crop. If you scroll down just a weeny bit and take off about 1cm you'll see that the image is stronger, though I'd also like some of the bottom cropped too.
#2 is a much stronger crop but she just looks fed up, bored and cold. I like the hair going over her face, but by asking her to open her mouth a little and giving her something to think about, an emotion to react to, then her expression will improve to fit the image.
#3 her arm and leg are beautifully lit, but her face is just starting to go into shadow and isn't as well lit. Also, she looks stiff, like she has been told to stand there. Do you talk to your models, and help them to relax? There isn't one of these images where she appears to be relaxed, and that's down to you - you need to work on helping her be relaxed within moments of starting to work with her. This is an overused location by your local photographers, so you need to work at creating something strong with the arches, and she isn't matching the strength of the locatoin.
#4 the location is good, but your positioning of her leaves wall coming out of her head. had you moved her slightly to your left then it would have worked better. Also, she is incredibly stiff in this shot - and being cold isn't an excuse - I have girls in summer dresses who I shoot in winter months, but the way you work with them helps them to be relaxed and to deliver on the job regardless of the weather.
#5 There's too much going on in this image so it's all distracting from the model, and she looks very bored. Her expression is not good at all.
#6 suffers from wrong lens choice as you have used a wider angle lens which makes her shoulder look huge. Also the positioning with the church makes her appear to be in Lilliput. Careful also with positioning of limbs towards the lens as this adds to distortions. Notice her fingers on her left hand - her fingers look short and dumpy because you have them pointing at the lens. Again, her expression doesn't work.
Hope that helps
Z