Hi Rob, Nice shot! I think you've done a pretty good job here. You ask for help.. I'm no studio photographer - others here certainly are, and will hopefully comment. Please take my suggestions for what they're worth - probably not a lot as I'm just drawing on what I've heard in lectures etc. Just trying to be helpful I guess. :)
I'm told you can do fine with a single light, or daylight. You can also build your own reflectors and diffusers and get identical effects to the stuff you would buy (though reduced convenience. A sheet of polystyrene makes a good white reflector, a bedsheet stretched over any sort of frame makes a fine diffuser (check for colour casts caused by dyes in the sheet though). Similarly a 15 denier stocking stretched over a filter holder will make a champion soft focus filter, adding softness but not giving an impression of a lack of sharpness.
In this shot, it looks like you maybe lit her from slightly above her face height - perhaps about where her gaze is going. This has given you a fair impression of shadowless light, but the directness is perhaps a little harsh and although she has a lovely face shape, the lighting perhaps hasn't improved it. I may be talking nonsense here, but you might try a higher light, for what is called "Butterfly lighting". It's easiest to see this if you take off the diffuser/softbox when you're setting up the light (but put it back on before taking the shot). Butterfly lighting is lit from fairly high above the subject, such that the shadow of the nose forms a butterfly shape stretching to about half way between the nose and top lip. This angle of lighting accentuates the cheek bones, reduces the impression of weight on the cheeks, and is a "classic" technique, still used today. (I'm just parroting other far better photographers) Hope this was mildly helpful - other more experienced folk - if I'm wrong please comment here as I will learn from that too! I still think you've got a nice result here, Rob! Chris