In case you didn't notice this is a BDSM forum and although it isn't specifically written anywhere, this has to be understood as relations where the submissive perform his/her task driven by de desire of satisfying feelings of his/her own (pain/humiliation etc... individidually or a combination of many) or driven by a purely intellectual desire of satisfying the master's wishes or, even more interesting, both sides at the same time.

Satisfying material needs is not part of the equation. Therefore, prostitution largely falsifies the very basis of a real BDSM relationship. Furthermore, BDSM is also based on absolute trust. There is no trust in prostitution. Trust also implies both D and s know each other very well. Do I need to elaborate?

Long story made short: As long as you pay her, you'll never have a BDSM relationship with her... no matter what she agrees to do or to have done to herself. This is the wrong forum for you.