Ashlee Hattermann, 13, was spotted in Mexico after missing from her Texas home since Dec. 1. Houston Chronicle

A 13-year-old girl was found in Mexico after she went missing from her Texas home Friday.

Ashlee Hattermann was reportedly dropped off at Thornton Middle School Friday morning but left campus to go to a nearby church. It was at the church that Hattermann convinced a Good Samaritan to buy her a bus ticket. The woman who bought the teen's ticket was unidentified but reported the incident to the police after seeing posts on Facebook regarding Hattermann's disappearance.

The FBI joined in on the investigation and tweeted Sunday that Hattermann was pictured in surveillance footage in Mexico. The FBI also reported that Mexican authorities are in cooperation with Hattermann's case. The missing teen reportedly passed through Laredo, Texas – roughly 300 miles from her Katy, Texas home.

"FBI San Antonio Laredo office joined in the investigation of mission 13-year-old Ashlee Hattermann, last seen in Katy, Texas on Friday," the tweet read. "Ashlee traveled to Laredo, Texas and crossed into Mexico late Friday."

According to Hattermann's parents, the teen experimented with social media in an effort to find "new friends." It was through social media that the 13-year-old apparently came in contact with a man in Mexico. Her parents found obscene photos of their daughter online and subsequently took her phone away and notified police, they told KSDK Sunday.

The conversations between the teenager and unidentified man did not end there, however, Hattermann's parents found a note written by their daughter calling the man "daddy" and referencing herself as "baby girl."

Debi Tengler, Chief Relations Officer with Arrow Child & Family Ministries, told KSDK Sunday that Hattermann's case was "sex trafficking 101."

"Immediately, it had signs of trafficking 101," Tangler said in an interview Sunday. "Often times it can be a Romeo relationship or a daddy relationship, where they become the caretaker or protector, the one who values and appreciates that child, building a sense of security in them and often times brainwashing them against their healthy, biological family."

Though the teen was spotted, the overall condition of the girl was uncertain. Local police and the FBI are still looking for clues to locate Hattermann.

Those with any information are urged to call the FBI at 210-225-6741. Hattermann was last seen wearing a blue jacket, jeans and brown boots. She's 5'7, weighs approximately 130 pounds, with brown hair and blue eyes.