Seems like you've got a lot of "firsts" going on at the same time. New camera, new model and new genre' of photography. Good luck.
About the image. It's tough to get a good image where the model is on her back, her head is in the far right portion of the image and on a downward angle. Following the *rule of thirds* if her head would have been more to the left the flat portion of her stomach wouldn't have contrasted with her rib cage since it wouldn't have been in the picture. I also think that if the lock of hair were in it's proper place that it would have helped to soften the angularity of her face.
A few of the comments made by other posters were inappropriate to a critique, but the hard truth is, it's tough photographing female bodybuilders whose masculine facial features are dominate. Study her face again and select the more feminine side and then play to that side when shooting glamour. Your make up artist should be able to help soften her angles too for a more glamourous look.
The picture below is of Alicia, (the torso below that is also hers), a long distance runner who works out but not for bodybuilding competition. With small amounts of body fat to soften the angles, body builders and runners have facial features that are more sharp and defined and is harder to make them look soft.
I look forward to seeing the images you come up with this summer.