Alice and Dawn, there are several sources where you can get lists of pieces and studies that are graded as to difficulty. String Syllabus for Harp and Guitar published by American String Teachers Association is one. In the U.K. try The London College of Music: Grade and Diploma Examinations in Harp; or Trinity College: FAX 061 946 1195. Australia: Australian Music Examinations Board,
I feel the exact same way! Sometimes the pieces my teacher gives me seem altogether too simple. Sylvia Woods’ Lennon and McCartney book for the harp has quite a few songs that give me a pedal work out. If I Fell is an example of a song from the book that challenges me. I suggest finding a book of music that you like, and picking one song to work on. I hope that helped, God bless!