A 34-year-old Texas woman was arrested after pretending to be a teenager and attending an East Texas high school for almost an entire school year.

Authorities say that Charity Anne Johnson posed as a 15-year-old student and was enrolled as a sophomore in the New Life Christian School in Longview. According to school administrators, not only did she successfully fool teachers and classmates, but she also received good grades.

"Everyone we talked to assumed she was a teenager like she said she was because she looked like one," the high school principal Stuart Newlin said, according ABC News. "She had friends. Everybody liked her."

The principal also told NBC News that "she was a good student, she was respectful and did her work, got As and Bs. There were no red flags going up at all, the kids loved her."

Johnson told school administrators that she was an orphan who received home schooling as a child and was admitted to the school in October 2013 under the name Charity Stevens. She also tricked a good samaritan into taking her in. 

"She came in with a guardian; there was no reason to be suspicious," Newlin said. "Usually, parents come in, they fill out the paperwork and we take their word for it. If they come from another school, you transfer records. If they come from home school, they don't have those records."

Officials are currently investigating her motives.

30-year-old Tamica Lincoln became Johnson's caregiver in March 2013 after they met at McDonald's, where they both worked. She says that Johnson told her that she needed a place to live because her parents died and her sister kicked Johnson out of the apartment. 

Over a year later, Lincoln discovered that Johnson had been living a lie. She called the police and had her arrested on Monday.

"I allowed her to come into my house," Lincoln said. "I was just trying to be nice and kindhearted and get her out of the situation she was in."

Lincoln said she was dumbfounded when she discovered that Johnson was not a teenager.

"She acted like a kid. She did her homework. She got good report cards," Lincoln said.

The truth was revealed after Lincoln received a phone call from a woman who ran a group for needy children that Johnson tried to join. Lincoln said that the woman had run a background check.

"I started looking into it. I contacted the manager that works at that McDonald's. He pulled up her file and the date of birth was 1979. The name was Charity Johnson."

Johnson was then arrested for "failing to identify" herself to an officer and is currently being held in the Gregg County Jail on a $500 bond.