difficult. and now they are trying to change the rules that govern lung donation for young children. if not in time to help their daughter, then to help others like her. our zain asher has their story. >> 10-year-old sarah wants to be a singer. ♪ how i wonder what you are >> her mother says if she gets a new pair of lungs next few weeks, her dreams could one be a reality. >> i'm not going to tell her she's dying because she's 10. >> sarah was born with cystic fibrosis, an illness that's damaged her lungs beyond repair. >> i used to go to school before i got oxygen. got to go to school and at least