My 14 year old, profoundly dyslexic son says he does not understand music, hates to sing, and hated elementary school music class, especially when finger plays and hand movements are involved. He can't remember the words, replicate the tune, or even differentiate between to similar songs. Unlike your dd, mine does not have a musical bone in his body, no sense of rhythm etc.
I agree with Cricket there may be some issues around CAPD - I've heard the same.
John Gabrielli (sp?) has done some research around the link between music and dyslexia.
