Hi Mike,
Please don't take this as criticism, or even advice, as I'm in no position to advise anyone.
Sometimes I find a person very attractive, but when I have an opportunity to photograph them, I'm disappointed. I can't quite get the right angle, or expression, for whatever reason, or the lights not right. Sometimes I'll photograph the same person on several occasions and never get a photo that matches my experience of the person. Much of this can be chalked up to my lack of photographic fluency, but I think there's more to it than that.
I think when someone is said to "not photograph well", it's often because the person's charms are not purely visual, but involve the whole of the person; their movements, gestures, voice, and even the way a person smells can trick our brains into believing we're seeing a great beauty, when in fact we're experiencing a great beauty on many sensory and even emotional and intellectual levels that don't necessarily translate in a photograph.
There's nothing novel in this idea, but when you're the one being tricked, it's easy to forget. I think doing justice to a charming person who "doesn't photograph well", is a great challenge, and a worthy one, and when you finally succeed in making an image that matches your experience of the person, it can be very rewarding. Best of luck, and don't give up!