The singer appeared at Barrington High School in the Chicago suburb of the same name on March 22 as part of the grand prize for the "Shine Bright Like A Diamond" contest, which the school won for a video highlighting the students' commitment to charitable organization and activities.

According to The Daily Herald in Chicago, students lined up for four hours on the first day of spring break to see Rihanna perform, but the singer failed to show up on time, leading to a shortened performance that some say was only 10 minutes long.

It's been three months since the show, but Rihanna is only now sending a mea culpa to the school, which reportedly spent $2,000 on extra security, along with signage and printing used to promote the show.

"We're certainly gratified to receive a contribution from her," school spokesman Jeff Arnett told the paper. "Even though this $5,000 gift has been long in coming, her management communicated with us immediately after the event and said she wanted to do something for the students. It didn't take any coaxing or pleading by the district. It was something they offered to do, and it took a while to work through the book keeping process."