If she has ADHD and not a lot of free time, I’d second audiobooks. It’s a good way to get into longer narratives, and you could get hooked on a series and continue in print, or move back and forth between print and audio.

My middle schooler has enjoyed the Battle of the Books books the last couple years but I just looked at the high school list and I don't know if they're as compelling. Fewer current titles for the older grades.

https://www.battleofthebooks.org/book-list/