GARY, Ind. -- Eighteen-year-old Raven Osborne is about to get her college degree.

"I graduate from college on May 5," she told CBS News' Jericka Duncan.

Raven Osborne CBS News

But when does she graduate from high school? May 22.

Yes, it's true; Raven gets her college degree two weeks before her high school diploma.

"When people hear that … they're going, 'What? How did she do that?'" Duncan said.

"Yeah they think I'm lying," Raven said.

She did it through online classes, year-round community college and two years at Purdue University Northwest. Her semester-long college courses counted as a full year of high school credit.

"Sophomore, that was the most work. I had five high school classes, four college classes," she said.

Raven attends the 21st Century Charter High School in Gary, Indiana. The school is surrounded by dilapidated buildings, a common sight throughout the city.

Everyone here is required to take college classes on a college campus in order to graduate.

Some get just a few credits. Five of this year's 43 graduates earned associate's degrees. And then there's Raven.

Kevin Teasley CBS News

Kevin Teasley started the GEO foundation, which runs the school. He uses state funding for tuition and transportation to nearby college campuses.

"The one line item I want to see go up every single year is how much I'm spending on college," Teasley said.

"When I started it was $10,000. Last year it was $85,000."

And how much did Raven pay for college? "Absolutely nothing," she said. "Not a dime."

Raven Osborne teaching younger students. CBS News

This fall, Raven will be back at 21st Century Charter.

Instead of paying for college, the school will be paying her salary, $38,000 a year to teach.