Teen performs CPR to save infant who stopped breathing at Wal-Mart

"The one thought that crossed my mind was, 'What if this doesn't work?' And I just had to push it out of my mind and keep going because I knew that's what I had to do," Snodgrass told ABC News.

Thankfully, the CPR worked.

“I can’t explain how happy I was when she started to breathe,” Snodgrass said. “It was a huge relief.”

Emergency responders say that the infant might have died without Abby’s quick thinking.

“We are exceedingly grateful to the young woman who helped our daughter,” the baby’s family said in a statement. “Our daughter is home and healthy, and we couldn’t be more thankful.”