( CNN ) -- Once again , the Murnaghan family is complete . After six months in the hospital fighting for her life -- during which her parents fought to change national policy on organ donation to save their now 11-year-old daughter 's life -- Sarah Murnaghan returned home to Newtown Square , Pennsylvania , on Tuesday . `` She just wanted to be with her brothers and sister , '' her mother , Janet , told reporters . `` I mean , she really just wants to be with her family . It 's been hard . '' Then again , life has never been easy for young Sarah . She suffers from cystic fibrosis , a disease of the secretory glands that 's passed through genes -- even if the parents of the person afflicted do n't have it . According to the National Institutes of Health , the disease often affects sufferers ' lungs , pancreas , intestines , liver , sinuses and sex organs . In mild cases , a person with cystic fibrosis may not be diagnosed until they are teens or , perhaps , adults . But for others , it can have a debilitating impact . That was the situation with Sarah , who has been in and out of hospitals her entire life . Speaking Tuesday , Janet Murnaghan credited the diagnosis with making her daughter especially tough . `` It 's a disease that 's really demanding -- ... it takes everything from the minute you 're diagnosed until you 're at the point where Sarah is at , '' the mother said . 'She 's spent her whole life fighting . It 's just a different mentality than your average kid . '' Even then , the past year has been particularly difficult . Sarah 's lungs had deteriorated rapidly -- much faster than anyone in her family expected -- and in May doctors told the family that Sarah had less than five weeks to live . Despite her dire condition , though , Sarah could n't get a lung transplant . She was the first candidate on the priority list for children in her region . But children 's organs rarely become available . In 2012 , there were just 10 transplants in Sarah 's age group , according to the United Network for Organ Sharing . Comparatively , there were more than 1,700 adult transplants in the same year . Her family felt transplanting an adult lung was their best hope . But it was n't possible : Sarah fell just shy of the requirement that anyone who gets adult lungs must be at least 12 years old . Perhaps taking a cue from their daughter , the Murnaghans fought vigorously to change that stipulation -- and like her , they succeeded . On June 5 , a federal judge issued a restraining order to prevent the U.S. Department of Health and Human Services from having the agency that oversees transplants apply the policy . HHS Secretary Kathleen Sebelius then directed the Organ Procurement and Transplantation Network to waive the rule . Even after that move , the Murnaghan family is vowing to keep working so youngsters get every medically sound opportunity available to get transplants . `` Kids on the system have died at three times the rate , '' Janet Murnaghan said . `` So we 're not letting go of it . '' June happened to be a particularly tough month for the Murnaghan family in many ways : Not only were they initially waiting for a policy change , but Sarah -- then 10 -- was clinging to life . Their dreams appeared to come true that month as well , when she received transplanted lungs -- from an adult . But it did n't take , the family revealed later . For several days , a machine kept Sarah alive . She got another chance in the form of a second lung transplant , which again came from an adult . Speaking more than two months after that happened , Janet Murnaghan said `` the lungs are doing fabulous . '' `` She 's weaned off the oxygen , '' the mother said . `` But she has the tracheotomy , ( which ) is helping her breath ... They just ca n't do it by themselves yet . '' With her discharge and ambulance ride home from Children 's Hospital of Philadelphia , Sarah is back where she belongs . But it 's not like things are all of a sudden easy for her . She still has trouble walking , relying on a walker to move . She will head off to rehab several times a weak . But Sarah will also start school -- from home , initially -- the week of September 9 . If all goes well , things will keep on progressing , says her father , Fran Murnaghan , who adds hat the goal is `` getting more back to regular life . `` Each day , she gets stronger , '' he said . `` We 'll be doing more and more normal things . '' Given all that she 's gone through , for Sarah , doing `` normal things '' will be an extraordinary accomplishment .
Sarah Murnaghan has cystic fibrosis ; her condition and her lungs deteriorated rapidly . The disease is a genetic disorder that causes the body's immune system to attack its own tissues, causing them to break down into toxic waste called fibrosis. The family won in court , as Sarah fought for her life ; she had two lung transplants in June . `` Each day , she gets stronger , '' her father says .