I like the hair light, it adds a nice touch to the image but on my un-calibrated monitor the image looks a little underexposed.
Also, the hair that dropped into the models face is a major distraction. You should always be on the lookout for these types of snafus (hair in the wrong place(s), bra strap showing, clothes pulling, etc) and when they happen correct them before you push the shutter button. Generally if you have a model already posed you, or an assistant if you are working with one, should make the adjustments but ask the model first before touching her.
Here is a similar photo for comparison. Keep working at it and don't hesitate to ask for help.
Re: My third photo shoot - critique please