The planet Andar was a fringe world between Republic and Sith space. Home to a variety of species, the planet was a brutal dictatorship, hoping to turn itself into a military power capable of withstanding either of its neighbors. The dictators realized just how doomed those efforts were when the sith fleet came, landed troops, and claimed Andar as property of the Sith Empire.
Many feel the transition will have little meaning. They will go from serving the royal family to serving the sith. But some sense this as an opportunity. The sith need people who know the planet and its politics, and they lack the proper numbers to handle everything themselves. Some believe this could be an opportunity to get out of the crushing poverty of the old regime and become something.
I'm picturing your character as someone who works in the royal palace with little status. She could be a guard, a servant, a slave to someone important, or just about anything. Whoever she is, she ends up in close proximity to one of the sith apprentices overseeing the occupation efforts. The sith sees her as intelligent and strong, but also senses the force within her. After observing her a little, he makes her an offer. He will take her on as his apprentice, teaching her what he knows of the force. All the people who once controlled her destiny will now bow to her, and she will have a chance to shape the planet that has been a prison to her. In return, however, the sith expects absolute obedience. She is a weapon to be used by him, but also a source of pleasure and release. In short, she is to submit when they are alone and rule her former superiors when they are in public. I'm picturing a fair bit of bondage and stuff like that, but I'd also like to get into the power struggles of the palace. Power draws enemies, and this is something master and apprentice must face together.