"We surprised our teacher with kittens because her cat passed away yesterday," Hanhart wrote.
The students at Joshua High School told ABC News they came up with the idea after their statistics teacher, Tonya Andrews, began crying during class one day.
"I'm sorry, my 16-year-old cat named Blondie died yesterday," Andrews said.
The trio then decided to get flowers and cupcakes in an attempt to cheer her up when Swindel suggested they also get her kittens.
"So my mom looked online to find kittens in Fort Worth that needed a home," Hanhart said.
Their plan was ultimately successful as Andrews cried tears of shock and joy, while asking "Are they mine?" as the students presented her with her new pets.