In December, Willingham's daughter began receiving unsolicited travel brochures at their East Alabama home.
A disturbing package addressed to the young girl contained a half-eaten doughnut, church bulletin, three dollars, and a written letter from Artur Bhuck of Santa Fe, New Mexico.
The writer claimed to be a 14-year-old who was bullied and asked Willingham's young daughter to email him.
The family reported it to investigators and, months later, learned that their daughter wasn't alone.
Willingham said, "It freaked me out again to know wasn't isolated. She wasn't the only one. There were lots of girls he was doing this too. I think the other kids were getting theirs at school, but ours came to our house."
Agents traced the email address from the letters and learned that there were more than 50 packages, tied to the account, that were sent to minor girls at their elementary schools in New Jersey, South Carolina, Virginia, and Alabama.
Agents also traced the IP address to websites where the user discussed girls' underwear and types of music to listen to when visiting 'pen pals' in Phenix City, Alabama.
Willingham said, "She came in and she cried. My husband talked about it and was like I'm not going to let anything happen to you. You're safe with us. And the police are going to take care of this now. So we know that this is a bad man."
While Willingham comforts her daughter, agents are searching for the predator. Parents are urged to call law enforcement if anyone receives a similar package.