Position should be adjusted, her back needs to be straightened more, it looks like she is about to fall backwards on to the bed. Future picture info, have the lady(s) behinds closer to the edge of the bed so there feet firmly touch the ground for stability. Make them smile, or have them look off right passé the camera lens, or make them look like their thinking of some sexy romantic fantasy while their eyes eye looking up in the northwest or the northeast position with a lushes enticing smile on her face(you never know what you might get out of those pictures). Maybe a little color splash, accent something on her that stands out to you the most that you want other's to notice when they see your photographs. Have fun, And keep on Snapping those Photos!