She Kept Her Sister's Last Tips for 4 Years. Then She Changed 350 Lives.

On October 12, 2014, a Pennsylvania high school teacher got the worst phone call of her life. Her younger sister, Katie Amodei, had died in a car accident in northeast Philadelphia. Katie was 29. She had been an EMT, organized charity runs, and that morning had worked the breakfast shift at the restaurant where she waitressed part-time.

A Purse Full of Tips

When Kristina Ulmer arrived at the scene, she asked a police officer to retrieve her sister's purse. Inside was Katie's final earnings: $80 in tips from that morning's shift. Kristina drove home with the purse. She couldn't bring herself to spend it. For four years, the money sat untouched - a small reminder of a sister who had spent her last working hours looking after strangers.

The Classroom Decision

In 2018, Kristina was teaching Ray Bradbury's Fahrenheit 451 to her freshman English class at Hatboro-Horsham High School near Philadelphia. She was worried her students were becoming numb to each other. She thought about Katie, who had always looked for ways to help people she didn't know. She went home, exchanged the old bills for crisp $20 notes, and added some of her own savings. The next day she stood in front of her 26 students, handed each of them $20, and gave them one instruction: use it for kindness.

What $20 Can Buy

The results surprised her. One student used the $20 to pay off library fines - and discovered it cleared the accounts of eight students, allowing four seniors to graduate on time. Others bought hygiene kits for homeless shelters, toys for animal rescues, holiday cards for veterans' homes, and small Christmas trees for elderly neighbors living alone. One student sewed hats for premature babies in a hospital NICU. Anonymous donors began sending money in, allowing Kristina to run the challenge again the following semester - and every semester since.

A Foundation in Her Name

The $20 Kindness Challenge has now run for six years, produced more than 350 documented acts of kindness, and raised over $7,000 in donations. Kristina has turned it into an official 501(c)(3) nonprofit, with the goal of giving grants to teachers across the country to run their own versions. A New Jersey teacher received the first grant in spring 2025. When students ask why she does it, Kristina tells them about the morning she found $80 in a dead woman's purse - and what she decided to do with it. "They're gonna save the world," she told CBS News.