Does your insurance include damages done to the instrument while OUTSIDE the home? Like at band/string camp, or at school?
Our policy does cover this. I know of one incident where one student scratched up another student's instrument (trumpet) pretty badly. Insurance paid to restore the instrument. I made sure of that because with the kids in marching band, things happen... .

These kids have to lay their instruments on the blacktop, grass and they get knocked off the bleachers etc...If at all possible keep an old flute or pick up a cheap one for marching band! Trust me out on the field, no one cares if your tone quality is perfect! 