Jenny Thomas has known that she was adopted since she was 4 years old, but she spent 15 years on an unsuccessful internet search looking for her biological family. Now, with the help of TLC’s new series “Long Lost Family,” she has finally found her mother, and it turns out they already knew each other.

Thomas had worked with Nita Valdez for 2 years when they were both working at a Rochester hospital. Thomas was a part-time patient care technician, and Valdez was a patient transporter. They met each other ten years ago, but neither of them realized just what they actually meant to each other.

“I was just in shock,” she told the New York Post upon learning they were more than co-workers. “I didn’t expect that, not in a million years.”

Adopted woman discovers she works, lives near her biological mother

Valdez, as the daughter of a minister, had been deeply embarrassed when she became pregnant out of wedlock, and so when Thomas was born, Valdez placed her with social services.

The episode, which is called Your Mom’s Been Here the Whole Time, is expected to air on March 13, while Long Lost Family itself premieres Sunday at 10 p.m. on TLC.

In the meantime, check out the sneak peek below with Thomas’ reaction coming in at the 1:04 mark.