Transcript for A mother and her long-lost daughter reunite after five decades of separation
Finally tonight the chance DNA test uncovering a secret transforming an entire family. I was over there checking. I had to come sit down. I just can't take this. Reporter: For five decades Karen Leslie has lived with a secret, a secret about to get off an airplane in San Diego. If I hear her voice -- Reporter: 52 years ago Karen got pregnant, but didn't have much money. She wasn't married and decided to give her baby girl, Erin, to a catholic adoption agency. It was hurtful any time you give up a baby. Reporter: Always hoping she would see her again. This is when she was 4. Reporter: As time passed that reunion seemed more and more out of reach. Karen would move away, marry, have more children. Out of the blue a question after a relative took an ancestry test. Were their more children? Karen said yes. I could not believe it. I couldn't wait to tell my brother. Oh, my god, you won't belie this. Reporter: Karen and her long-lost daughter started texting and decided to reunite this weekend. Cameras capturing the moment they saw each other. We're not going to cry. Oh, my god. Look at you. I know. Reporter: Mother and daughter have a lot of catching up to do saying this about meeting face-to-face. How do you love somebody you never met? You can love somebody you never met. She gave me life. Step back and revel in it. Thank god. He wants us together. Reporter: We want to thank our affiliate KGTV for their help with that story. We want to thank you for watching. Tom llamas in New York. "Gma" first thing in the morning and David Muir back here tomorr. Have a great evening.
This transcript has been automatically generated and may not be 100% accurate.