Hm. I've been in a similar situation - but it was a friend and she was more imitating my lighting and some of my ideas - but it was more that she was learning and improving and being ispired by me.

Which is actually very cool.

Based on the images that you posted - you really have nothing to worry about, the quality and experience is definately on your side. As time goes by, the model will develope her own style and stop imitating you.

I would just stop photographing her if it bothers you that much. 

On another note - I recently took up modeling to work with other photographers and see how they work with models to improve my own work - I have no intention of copying their style or shots, but it's very cool and interesting to see it from the other side.

~Saryn