Can she try out for drum major? My D was chosen to be drum major, but some schools have try-outs, and have more than one DM. D was told this was something she should put on her college app., as it is a leadership position.
However, if DM is not an option for your D, I would think that simply sticking with marching band for all four years shows commitment and dedication to that activity. There is also a lot of self-discipline involved in marching - exact marching skills, time management, learning the music and choreography, etc.
Btw, this is the first I’ve heard about scholarships, etc for 4-year marching band members. Hmm.