An engineer by trade, Emily Lewis’ proudest accomplishment is being mom to this bunch of six.

“We homeschool all of them so we get to talk about lots of stuff all the time,” said Lewis.

Their family talks turned pretty serious. At 40, a nagging headache and sharp leg pain landed Emily in Urgent Care. Doctors told her it was meningitis. Then they found a heart murmur, and eventually an enlarged blood vessel in her heart.

“Her aneurysm was growing pretty fast, which tells us that it's not strong and is at risk for rupturing and taking her life,” said Dr. Mark Pool, cardiac surgeon at Texas Health Dallas.

Dr. Pool performed surgery to replace a section of Emily’s heart. But it gets tricky.

“The heart has to be stopped in order to replace that part of the aorta,” explained Dr. Pool, who used a technique called hypothermic circulatory arrest, which means he froze Emily’s body for 21 minutes.

“We cool the patient down to nearly ice cold, and then completely shut the blood flow off,” said Dr. Pool.

To the ordinary person that may sound like death, but Dr. Pool said it’s what kept Emily alive.

“The brain can only go about three or four minutes without blood flow at normal temperature,” he explained. “But the colder you make the brain, the longer it can go."

With part of her heart now replaced, Emily is happy to be 100 percent back to herself.

“So are my people -- my little kids,” said Lewis. “It’s amazing -- it's a gift, all of it. We're not promised a single day, so all of our life is a gift.”