Martial arts and for several reasons. She can be with the MC, they find out what happened to Riona, and Maya needs to be protected. Maya doesn't like fights, but Josy does. Either Josy is with Maya, Sage or the MC.
For Riona, I'm hoping Quinn isn't behind this and she'll help her friend. I think to myself that this will be the path to redemption for Quinn. Quinn finds out about the kidnapping over the phone so it's Vinny. In my playthrough, CHICK MC, Quinn will not call the MC. I hope so Quinn will make the right decision. She got all the information she needed from Tommy. That Vinny doesn't shy away from gun violence, that his gun is a real gun, and that the MC wanted to call the police. Of course, Quinn would probably end up in prison, but she would have done the right thing and can be forgiven. The other side of the coin would be for Tommy to want to be the bigger man, bigger than the MC. But that wouldn't end well for Tommy.
In EP1 already said that she would be interested in a self-defense course. It would be a wonderful opportunity for Josy to share a hobby with the MC.