Keep battling with her. I know that seems like unhelpful advice, but the best thing you can possibly do to nurture her confidence is continue to train with her while at the same time giving her positive reinforcement. Have her spar every day (either with Rye or in battles against other friendly trainers), and couple this with focused move practice. Every time she successfully executes a move, say encouraging words to her, and after every battle she fought hard in, even the ones she didn’t win, give her a treat. Most importantly, if she struggles to use a move or loses a battle, speak to her softly and reassure her that she did her best. If she allows it, show some affection as well.
It’s important that you push her (gently, of course) to keep trying. The more she battles and trains and the more she hears you encouraging her, the easier it will be for her to feel both confident and comfortable in her abilities.
Best of luck!