Mackenzie's stepsister, Katelyn Salmont, was featured twice on 7th Heaven. She played a girl with cystic fibrosis, which Salmont suffered from in real life. After a double lung transplant, Katelyn was featured on the show again to spread awareness. Sadly, she died in 2008 due to pneumonia. Rosman is the national honorary chairman for CureFinders, a school fundraising program to help fund the search for a cure for cystic fibrosis.