I don't think you have a practice problem. I think you have a competition level problem. She is bored because she is striking out 24 out of 30 batters, so what's the point of practicing? How much better can you get than that?
I'll bet if you raise the level of competition so she's striking out 10 out of 30 batters, or 6 out of 30, she'll be a lot more interested in practicing. She will have an incentive to improve.
I'll bet if you raise the level of competition so she's striking out 10 out of 30 batters, or 6 out of 30, she'll be a lot more interested in practicing. She will have an incentive to improve.