Mom: Hearing son's heartbeat in girl "magical"

Heather Clark and Esther Gonzalez never met until this weekend, but their lives had formed an unbreakable bond some two and a half years earlier, reports CBS News correspondent Ben Tracy.

Clark lost her seven-month-old son Lukas in June of 2013.

"Lukas was very energetic, very smiley," Clark said. "Losing a child, you lose yourself. I was like, I don't ever want any mother to go through what I'm about to go through and that's when I decided to sign the paperwork and save somebody else's child."

Clark decided to donate his organs, including his heart. Gonzalez's daughter, Jordan, was the the lucky recipient.

By the time she was 18 months old, Jordan had undergone six surgeries because of a congenital heart defect. A transplant was her only hope.

"She would be so selfless to be able to think of another family while she's going through her grief," Gonzalez said.

Living in different states, the two mothers had been in touch only through the mail, social media and phone calls in the years since the transplant. It wasn't until they finally decided to meet in person that Clark was able to listen to her baby's heart beating inside Jordan's chest.

"It was magical, it was crazy, it was sad," Clark said. "There's absolutely no word, no explanation for it besides just magic and wonderful."

Clark said the joy of seeing Jordan healthy is helping her deal with the pain of losing her son.

"Knowing that she's so smart, and so respectful, you know, it just makes it so much easier," Clark said. "Because she's just exactly what I could picture Lukas being right now.