So, what's appropriate for such a letter? Should just the teacher's impressions from the lessons be in it? Or should recitals, competitions, festivals, evaluations be mentioned, too? Is it appropriate to tell about other people's (teachers, musicians, other students' parents

) impressions of the student's playing in that letter or should there be strictly that particular teacher's observations only? What kind of musical terms and expressions the student's piano skills are usually desribed with?
(I think I'll talk to the teacher once more and try to convince her to write that letter, and if not, I'll try to write it by myself (there are parents who teach their own children, aren't there?

); in any case I'll need some advice on the imformation mentioned above - either to provide the teacher with it or for myself).