Check the admission requirements. Tanglewood is for 18 and over high school grads: BSO | | Tanglewood. You could look at BUTI
Similarly, Aspen doesn’t provide housing for under 18. They used to be more welcoming to under 18 admissions than they appear now. Solo Piano | Aspen Music Festival And School
When “ours” went through this in the early 2000’s, several of the “elite” festivals (Music Academy of the West, Aspen) did allow and encourage under 18s, usually with the requirement of off campus housing with a parent. The under 18s that I knew generally fit in and had a good experience, but they were also the kids that went on to Curtis and Juilliard with full scholarships. Their musicianship was the level of the conservatory students attending. I knew violinists, not pianists.
In “our” cases, the kids followed primary teachers to a “major” place that had both an under 18 and college age program. Different dorms, different rules, other facilities and program the same. They went from freshman year to high school graduation. During college, on to fellowship programs, high level. By the time they were approaching college graduation, they were sick and tired of festivals. Didn’t attend any during graduate programs.
I did feel that the high school summer festivals were good, but noticed “diminishing returns” for college years. This was for our string players. They attended major conservatories, so I felt and they seemed to experience that the summer festivals were not terribly different from school year - different mix of students, some different conductors, maybe a different studio teacher (good and bad reactions there!). “Ours” encountered many of the same group of students no matter where they were - a summer festival from high school years or college years or school year conservatory colleagues.
Individual experiences will vary - our kids may not represent all. Wind player experiences would be quite different, I’m sure. Piano - I don’t know, we didn’t do those festivals.
Changing thoughts - Does Eastman still have a good high school summer piano program? At her age, if not following her current teacher, I would be looking for a great studio teacher - either for violin or piano - at a summer festival. Or, if chamber music is not a part of her current routine, perhaps look for a place strong in that. At 14, if you happen to pick a less than optimal festival, all is not lost. She can “make-up” any time she missed by an under-challenging program.