Ahoy! Good question. I would ask her to allow you to take say facial images in private and show her the results. You never know, both of you may be surprised at the results. Ask her not to look directly at the camera to try and get a more natural candid image. This may make her feel less 'insecure'. The chances are that you'll get the money shot to which she will be delighted with. I'm no expert, and am ugly as a wart on a frog's backside, but, it may help her to feel more comfortable with herself. Also, ask her under what conditions she will feel most comfortable with (one on one - with friends etc). For Pete's sake, do not get her to anything she feels uncomfortable with. If you get an image, just remember, no-one will be criticising looks or appearance. Most of us on here will offer advice on the image alone in terms of angle, colour and other basic stuff, not the subject. Have a go, and post on the forum if she is willing to model for you.
Also, with post processing, many things can be done with an image, such as filtering as with this one of one of my
grandaughters. It can really change the appearance of the overall image.