Ultimately this topic boils down to 2 things. Courage and (in)securities. Required of both parties in order to make things work. Courage to love, and security within oneself, both her and yourself. As I've seen over the years, the SP, although sees many guys a day, is probably more insecure in putting her real self out there to be with you as she's seen so many examples of how men can be. You on the other hand just cant get over the fact that she's 'working'. Its not easy but its what it boils down to. And its not specific to a relationship with an Sp, its relationships in general.
If u love her, then see beyond her work, and love her. Make the distinction between her and her chosen line of work. At the end of the day is the issue with her, or yourself? See with your heart, not with your brain.
Look at it this way, this butterfly chose to be in your garden. She could easily fly over to the next or the next, other gardens with maybe more plentiful and fragrant flowers where she may reap bigger rewards. Yet she chose your garden to dwell in. Believe in that, work on improving your garden to make her stay the best it possibly can be. Nurture your garden, and give her the best you possibly can. Plant more flowers, grow greener grass. If at the end of the day this butterfly decides to move on, you'll at least have a greener bounty for the next butterfly to come along. Nurture and be the best you, the rest you leave to time.
Usually we are our own worst enemies in this situation. But work on yourself, be the best you for her, and see her for her, not her work.