A friendly face was missing from Anderson Elementary School in Frisco for several weeks.
Instead of teaching students, 41-year-old Sunny Sinclair, worked up a sweat on NBC's hit reality show "The Biggest Loser."
"[She's] one of the funniest people I know, and I'm not kidding you when I say that," said co-worker and friend Mandi Jenkins.
Jenkins said Sinclair never discussed her weight. According to the show's website, Sinclair is 277 pounds.
But when a school nurse asked Sinclair if she wanted to audition for "The Biggest Loser," she jumped at the opportunity, Jenkins said.
"She surprised me that she would do something like that," Jenkins said. "But I think she saw it as a once-in-a-lifetime opportunity, and it was a life change for her, a health decision to become healthy."
Jenkins said Sinclair auditioned in March and found out she was officially on the show in May.
"She ran down from her classroom and said, 'They called me back. I'm leaving next week.' So it was very quick, and then she left," Jenkins said.
Sinclair returned to teaching at Anderson Elementary on Monday but is unable talk about her progress on the show.
But Jenkins said she has no doubt her friend could ultimately win.
"As soon as she got on the show, I said I wouldn't be surprised -- and her family, too said the same thing -- I wouldn't be surprised if she won it."