cystic fibrosis. sarah's family was so desperate to save her life, they were willing to do anything to get her the newe so desperately needed, so they sued, challenging this ruling that made it nearly impossible for children to get adult donor lungs, and they won. earlier this year, she was put on the waiting list. the first lung failed, but after much doubt and concern from her doctors, her progress is remarkable. jason carroll has this exclusive update on her recovery. >> four months ago, sarah could barely move in her hospital bed without help. after receiving two lung transplants. the surgeries necessary because she was dying from cystic fibrosis. her goal then was very clear. >> i'm not going for easy. >> you're not going for easy. >> i'm just going for possible. >> this is what possible looks like now. sarah at home in her bedroom, doing physical therapy with her mother and her home nurse nearby. >> shoulders back. >> she's walking, thinking about christmas. >> i asked for a furby. >> and focusing on how far she has come. >> i knew what i was going through was possible. and it was possible for m