You have all you need here to take a good model image.
On my monitor, the overall image seems a bit soft, especially her face. I assume you know about sharpening before you upload by now, so perhaps the large original is also a little soft?
You used shutter priority, which would not be most photographers choice for this situation. Its aperture, as Moira suggested thats most important in a studio like setting, where you have control over the light. Even if you still selected f/2.8, use Aperture, or Manual. Then its you that decides the depth, not the camera.
Did you decide on -2/3 after you took some shots with no negative compensation? If not, why did you decide on -2/3?
The Canon uses TTL2 flash control, assuming you are using Canon speed-lights? Look at the front edge of the table top. Its reflecting a lot of light back to the camera, and may affect exposure, causing the flash power to drop. It appears underexposed, and this in addition to the -2/3 could be the problem. You would probably need to re position at least one flash to avoid the reflection, or, dont use -2/3. Theres a very bright area on her chest, her left side, that indicates too much light concentrated in one spot, - be careful to diffuse the light, perhaps even more.
Its very important that you use a single focus point, and not multiple focus points for this shot, and place the focus point on her eye nearest the camera. I wounder did you do this?
I think that you are improving at this type of shot, - so take the feedback into account, take your time, and take control over aperture. F/4 or 5.6 would be better here. To control the light, move the flashes closer, or further away. Try setting one flash to half the power of the other, Experiment.
The mod is sharper, cropped a little. Colour tone is a lot less red, and sharpening applied.