I agree with Derrel about your second and third images. If you don't go with an uncropped vertical for those, at least consider a tighter crop (square, maybe?). In these I don't think the backgrounds add anything to the shots and can be a bit distracting. However, in the last one I like the amount of dead space blank wall left in the shot. What you've captured of her conveys a feeling of motion, of vitality, to me. Going vertical or cropping this to remove that dead space would box her in too much, leaving me feeling that shel is cramped in the frame rather than free.