By Stephanie Stahl

PHILADELPHIA (CBS) – There are several new developments in a desperate struggle to save a Newtown Square girl’s life, including a congressman getting involved.

The family is fighting rules that limit the child’s ability to get a lung transplant.

There aren’t enough pediatric lungs, and transplant rules say adult lungs have to go to people over the age of 12 first. But Sarah Murnaghan’s family says that rule is unfair and that their daughter, who only has weeks to live, is facing age discrimination.

Ten-year-old Sarah wants to be a singer, but she needs a lung transplant to live. Her parents have been with her constantly while she waits at The Children’s Hospital of Philadelphia. Sarah was born with cystic fibrosis.

“She worries that she’s dying, because she’s not — she’s a smart kid. And she says to me, ‘Mommy, will I wake up tomorrow morning?’” said Janet Murnaghan.

Organ donation rules require adult lungs to be offered first to people over the age of 12. Sarah’s parents say that’s not fair.

“Rules are meant to be broken. My child is not a statistic. She’s a person,” said Janet.

Sarah’s parents have launched a public relations campaign to try to get the rules changed.

An online petition in support of Sarah now has over 40,000 supporters, and Congressman Patrick Meehan sent a letter to the Secretary of Health and Human Services requesting that she address the tragic unfairness and act to give Sarah a chance at life.

“It tugs at my heart. It’s not a perfect system. There is no perfect system. It’s the best we can do right now,” said Dr. Stuart Sweet, who is a board member of the United Network of Organ Sharing.

The organization issued a statement that says the rules can’t be changed for individual cases.

“If I change the system to give Sarah an advantage, there’s another patient, very likely an adolescent, who then gets a disadvantage,” said Dr. Sweet.

Sarah’s been on the waiting list for 18 months. Her options are limited, but she’s not giving up hope.

“I’m not going for easy. I’m just going for possible,” said Sarah.

Sarah and her family say they are very happy and grateful for the care she is getting at CHOP.

The hospital isn’t commenting on the case.

3 On Your Side also reached out to the Department of Health and Human Services, and we’re told congressman Meehan’s letter will be responded to promptly.

Stephanie Stahl