I don't think she has any "mental health issue", but she certainly isn't where she'd like to be in life. I can't blame her, but again, I don't think clients would be "taking advantage" of a mentally ill person just to be clear.
She's definitely not likely to be excitable if she's not into you as others with a focus on the GFE would be, so I can understand why not everyone would benefit ideally from Honey, but there's no denying how spectacular her body is and I found in my experience ("YMMV") that her GFE with me was quite good (once she opened up).
Remember that these women are people, too - talk to them, make them feel comfortable, engage with them, and your experience will be better if they're not on edge.