When Katheryn Deprill was just hours old, her mother left her on the bathroom floor of an Allentown, Pa. Burger King.

The year was 1986, and Deprill was quickly discovered by patrons and workers at the fast food joint. She would be raised by her adoptive parents, grow up to become an EMT, get married and one day have three children of her own.

All while never knowing her biological mother’s identity.

“Unless you’re adopted, you’re not going to understand that piece of you that feels like it’s missing if you don’t know who your parents are,” Deprill, now 27, told FoxNews.com on Monday.

Bothered by doctors’ questions about her family’s medical history, Deprill earlier this month decided to seek out her mother, posting a photo on Facebook of herself holding a sign asking for help.

“Looking for my birth mother. She gave birth to me September 15th 1986. She abandoned me in the Burger King bathroom only hours old, Allentown PA,” the note says. “Please help me find her by sharing my post. Maybe she will see this. Thank you.”

A little over one week later and nearly 27,000 people have shared her story – but still no sign from the mystery mom.

Deprill learned about her abandonment as a 12-year-old, when her sixth-grade teacher assigned the class to a project focusing on the students' family backgrounds. Deprill came home and demanded answers from her adoptive parents, Brenda and Carl Hollis. They slid a scrapbook in front of her that held newspaper clippings from 1986.

The articles explained how a Burger King patron had heard a baby's cries and discovered Katheryn on the bathroom floor. How a restaurant worker then called police. How police were trying to track down the mother.

At first, the preteen thought there was something about her that had pushed her mother to abandon her. But as she grew older, she began to not only sympathize with her biological mom, but become grateful that she never used drugs or alcohol during her pregnancy, allowing Deprill to grow up healthy.

“I can’t imagine what she had to go through,” Deprill said. “She could have been in a very abusive relationship. There are so many things that could have been, and you don’t know until you walk a mile in her shoes.”

Deprill insists that no legal action can be taken against her biological mother, and adds that her cause has spurred other people to look for their birth parents as well. And she says her story serves as a reminder for parents who are unable to raise their children.

“There’s always an option to just not leave your baby,” she says. “Adoption is just a wonderful thing.”

FoxNews.com’s Karl de Vries and The Associated Press contributed to this report.