11 year old Sarah Murnaghan is getting healthy and strong after her double lung transplant that changed the rules of how organs are allocated.

Six months after a life-saving double lung transplant, the Pennsylvania girl whose parents changed the way the organs are allocated in the U.S. is growing healthy and strong — and she wants a Furby Boom for Christmas.

Sarah Murnaghan, 11, can breathe on her own and walk by herself for short distances. She speaks in a clear, calm voice, even on a day with a slight scare over too much congestion in her chest.

“The morning was a bit rough, but I’m feeling a bit better,” she told NBC News by phone Friday.

That simple sentence is priceless to Sarah’s mom, Janet Murnaghan, who, with her husband, went to federal court to force the Organ Procurement and Transplantation Network, or OPTN, to alter its rules and allow the child to be considered for transplant based on how sick she was, instead of her age.

“When we started, we thought we were going to lose Sarah,” the Newtown Square, Pa., mother told NBC News. “People have criticized me for going to court, but what other choice did I have?”

Sarah’s quest for a transplant was among the top health stories of 2013, raising questions ofwhether it’s ethical to change the way the nation’s scarce supply of organs is allocated based on the case of just one child.

At the time, officials — including Health and Human Services Secretary Kathleen Sebelius — argued that such a request jeopardized the fairness of the overall system.

“I would suggest, sir, that, again, this is an incredibly agonizing situation where someone lives and someone dies,” Sebelius told Rep. Lou Barletta during a Congressional hearing.

Murnaghan said she’s still angry at that comment — and at Sebelius, who denied her daughter’s appeal.

“When she made the statement that somebody has to die, she stepped over a line in me as a mother,” said Murnaghan, 39. “There was a lack of compassion, a lack of awareness that one life does matter.”

Since June, at least nine other children have requested exemption to the existing rules, which prevent kids younger than 12 from being considered for adolescent or adult lungs until those organs have been offered to the over-12 groups first. The Murnaghans successfully argued that the severity of a child's illness, not age, should be the key factor in being considered for the adult transplant list.

Two of those 10 children received transplants under the OPTN exception, including Sarah, who got two sets of lungs because one failed. Three children received transplants from the original waiting list registration and four are still waiting, according to records from the United Network for Organ Sharing, or UNOS.