Mariah Walton grew up struggling for every breath. Now 20, she awaits a heart and lung transplant, in part because of a congenital heart defect she said could have been fixed — if her parents had only taken her to a doctor.

Her parents refused to seek medical care because they believed she could be healed through prayer.

Now Walton believes it's time for her parents and people like them to take responsibility for endangering lives.

"I think it's time to prosecute them," she said.

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Walton is supporting legislation in Idaho that would require medical treatment for children in imminent danger of dying.

Some Idaho lawmakers have expressed concern over the proposal, saying it violates parental rights.

"You know, it's a First Amendment right, the freedom of religion," said Idaho state Sen. Lee Heider.

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Currently, state law protects parents from prosecution if their faith prohibits them from seeking medical care. The law shields parents even if their child dies from a treatable illness.

Walton's mother told NBC News that she did pursue natural medicine for her daughter. She also said she didn't realize how sick Mariah was when she used to gather the family to pray for her.

The proposal has yet to be scheduled for a hearing.

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