Finally found a reference image that fits well with what I have in mind.
However, as you can see, I didn't like the position of her legs ; maybe I could have worked out something with the same pose, but then again.. I wanted to play around a bit and see what can be done to make her more "uncomfortable" or tensed maybe. So I used the biped in 3dsmax and tried to match the pose in the reference photo with the proposed sketch.