Transcript for Family reunites after nearly a century and an ocean apart

Finally tonight, an ocean apart and decades in the making, one family reunited at long last. Here's ABC's John donvan. Is she in the wheelchair? Yes. Reporter: Rarely does a family reunion take close to a century to be realized, but that was the time frame involved the other day at Houston's airport when a 93-year-old American, that's Una pereira there -- Don't get up. Reporter: -- Stood up to meet her British sister Wynn, aged 88 and her British brother John, aged 89. Theirs is a sibling reconnection that happened first using technology. Somebody calls. Oh, you call that Skype. Yeah. Oh, I wasn't using Skype. I was using an iPad. Reporter: But their separation took place in an era that held on to secrets. Una was born unwanted in England in the 1920s and placed so young in a convent near London that she had no recollection of where she had really come from. Just a vague memory that a few times a woman with two small children made some visits. And then they disappeared again, and I was just a little kid, so I went a long time without anybody. Reporter: Una spent decades wondering about those memories but it was her grandson Christopher who did the detective work. She had said if I win the lottery, I would go find out who my mother is. Reporter: Christopher tracked down the convent records, got the necessary permissions. And eventually they broke to us and gave us Wynn's information. Reporter: And so reunited in Houston with another meet-up plan next summer in England and after that whatever time will allow after 90 years of waiting. John donvan, ABC news. So thankful Una finally found her family. We thank you for watching. I'm Tom llamas in New York. "Gma" first thing in the morning and David Muir right back here tomorrow night. Have a great evening. Good night.

This transcript has been automatically generated and may not be 100% accurate.