I am not a mother, but as a 20 y/o daughter I was in a similar situation. I played clairinet though...from 4th grade through 8th...and then high school came around.
I fought my dad about being in the marching band because those kids are tortured at my school
I wanted to make new friends and re-invent myself...which through my eyes was impossible in a band iniform.
I also wanted to GO to the football games and enjoy them. I instead used drama class as a creative outlet and found some of my best friends.
I know how irritating it was to my father but sometimes you just have to follow your gut and try something new in high school.
Im sure your dd would not be this stubborn if it didn't mean so much to her not to be a part of the band.
This all being said you sound like a great mom who only wants to best future for her daughter. (hugs)
But dont worry! There are so many other ways to get scholorships! Lots of ways that she would be so happy about
Best of luck.
p.s.
Im sorry my spell check won't work...its driving me crazy too! grr