I have a 14yr old student — playing harp for 2 years (after years of piano) — talented and bright — but high school is starting and many things pulling at her now.
Have you checked the books (classical and popular) by Barbara Brundage and Ray Pool? Also by Louise Trotter. Depends on your student’s taste in music. Maybe she’d like Matt Mayberry’s arrangement of “Clocks” by Coldplay. It’s available from Vanderbilt for either lever harp or pedal harp, so be sure to get the right one.
Plus, there is “New Blues” by DHC (Deborah Henson-Conant), which is a harder piece but something your student might be motivated to work on in the future. The Kater links I included above have links to videos of some of the pieces and you can certainly find many of the pieces (including Nataliana and New Blues and other Kater works) mentioned in this thread easily on Youtube.
I have a 13yr old student that has been playing lever harp for 4 years. She has played many pieces of music (classics, etc.); however the pieces that keep her coming back to the harp are Frank Voltz’s jazz pieces.