When Katheryn Deprill was just a few hours old, she was abandoned inside a Burger King restaurant in Allentown, Pa., in 1986.

Now married and a stay-at-home mother of three children, the 27-year-old woman who became known nationally as " the Burger King baby" is on a mission to find her birth mother.

Even though Deprill was adopted, she always had questions about her birth family. Five days ago, her adoptive mother suggested that she take her search to Facebook.

She did, posting a photo of herself holding a sign that read, in part: "Looking for my birth mother. Please help me find her by sharing my post."

In an interview with "Good Morning America," Deprill said it "just didn't register" in her head that she was abandoned.

"Everyone wants to know where they came from," she said. "I really want to know. … I want to see someone who looks like me. Maybe I have brothers and sisters. That would be so neat."

She also wants to know more about her family's medical history.

Deprill was found in the bathroom of Burger King on South Fourth Street in Allentown on Sept. 15, 1986. Someone heard her crying and told staffers, who came in and found her lying on the floor.

As a child, Deprill always knew that she was adopted, but it wasn't until she was 12 years old that her parents handed her a scrapbook with newspaper articles about her.

"I opened up the first page, and there's a picture of me," she said. "Then I turned to the next page and there it was, all the newspaper articles - the Burger King baby. My mother who adopted me saved all of the newspaper articles."

People are responding to her plea. More than 15,000 people have already shared the photo on Facebook, helping Deprill expand her search across the globe.

Deprill said she isn't angry about what happened to her. In fact, she wants to thank her birth mother.

"I am so thankful that my birth mother didn't throw me away. She didn't put me in a dumpster," Deprill said. "She could have been very young and felt very scared. … I can't even imagine being in her shoes and being alone and have to walk away from her baby."