Personally, I don't believe for an instant the idea that Courtney had never fought until she met Bill, and that she was only doing it because he thought it would be a good way to get her out of her comfort zone. No one could master all those judo throws in a few weeks, nor could they do so without partners approximately their own size to practice with. It's also obvious that she has the instincts of a fighter, which are not those of a victim. It's also true that the kind of men who enjoy bullying women are turned off by women with fire in their bellies; the type that excite them are the ones who display fear.
So my theory (What is it, that it is, this theory of mine?) is that Courtney's been fighting since the age of eight and thrown out of more dojos for excessive zeal than Chris Christie's had hot dinners. And that Bill, with the leisure that money alone affords, had been attending tournaments and hanging out in gyms and dojos for some years on the lookout for a girl through whom he could fulfil his own fantasies, and either heard about Courtney's killer streak or witnessed it in action at some tournament where she was disqualified for deliberately injuring an opponent, and thought: "that's my girl".
That's my theory, (that I have, which is to say, that is mine), and it's based on hard fact: or, rather, a catfight story set in Taiwan (but written in Spanish) in which the villainess is a vicious and very beautiful American fighter who was recruited in her early teens by a Taiwanese promoter who saw her at a tai-kwon-do tournament in the States and knew a star when he saw one.
So, although it's my theory, it is, er, stolen. Unlike that of Anne Elk (Miss):
https://www.youtube.com/watch?v=cAYDiPizDIs&t=3s