No fault with your cute little model, but the bright flash (presumably direct from the camera) is too harsh and casts a bad shadow. If your studio is large enough I might try putting more space between your model and the backdrop and using a shallower DOF so the background is less noticeable
Great attempt this type of shoot; can be a struggle to get right take it from me.
Things I can point out to help you in the future are:
Move the model away from the back drop as much as you can. I try to keep them at least 10 feet away from the back of the drop.
Try to avoid hitting your subject with direct light / flash. Direct light isn't very flattering and leads to harsh shadows and abrupt fall off. Defusing the light will make this much more appealing. You can do this with just about anything around the house, paper or a white cloth work well.
If you are using a speed light then there are other options available to you as well. Move it to either side, use bounce or reflectors to direct light, and above all, EXPERIMENT!
These are just a few pointers to help you on the path. Good luck and keep shooting!
You should have brought the light closer to the subject (or you could have used something like a bed sheet to diffuse the light, or both), to reduce the sharpness of the shadow cast on the back wall.
The shadows in this shot are overwhelming. Her outfit is dirty at the knees and her eyes are not showing which is very important for a modeling agency to see. Looks like she would like to be a model though but I have to give this shot a 3.