if she was housed at the school a while then she could have permanent damage or she might just have a thing where she rasps- i don't think it's too big of a deal if she's active and such, it might sound bad at times but she might just rasp all the time kind of like my rabbit does- he was always kept in a cold place in his last home so he kind of breathes funny and rasps occasionally now but the vet's pronounced him with clean, healthy lungs...
if you got her from the school, it will probably be hard to figure an age, but also, if she is an older degu, then she might rasp anyway, most animals do begin to breathe funny and rasp as they get older (also another reason my rabbit has funny breathing), just in general, everything starts to breathe funny as it ages, she might just be an older degu, too
~ Proud mommy of rabbits, rodents, and a dog ~