"[I'd] like paint yellow when I was happy and blue when I was sad or red when I was angry or green when I felt sick," she said.
Now the 15-year-old high school sophomore in Indianapolis, Indiana, is trying to bring art -- and a smile -- to other children in the hospital with Emma's Art Kits.
Now, she's blind in her left eye, has no peripheral or depth perception in her right eye, and has no short-term memory.
Her mother, Lori Stumpf, said it had been a really long eight years for Emma and the family.
"It's been crazy," Stumpf said.
Last year, Emma's father, Greg Stumpf, said the family almost lost her twice. Emma is now finally stable.
"She's always happy, you know. She's always smiling and she's always positive and trying to fight to go forward so I think a lot of that's rubbed off on us," he said.
She created Emma's Art Kits, which enables young patients who are unable to leave their beds to participate in art therapy. It's part of her mission to make others smile.
The kits come in a cellophane bag and arrive bedside in the hospital with all the supplies a young patient needs, for everything from painting and collage to drawing and coloring.
She said the art kits were helpful for her because she wasn't able to go to the playroom or the craft room and the art therapist wasn't always able to come to her.
"They get everything they need inside," she said.
The idea started with a doodle book and a cart she'd saved up almost $200 for to wheel around the hospital as she delivered art kits. She even does the personal shopping and decides what goes in the kit.
Laura Hayes at Cancer Support Community helps promote Emma's Art Kits.
"Art therapy is an amazing tool. It's a real way for people to work through problems," Hayes told ABC News. "Words are so limiting and art gives people another way to talk about it."
The kits are in 15 hospitals in the U.S. Emma's goal is to bring art to as many patients as possible in every state.
"I love seeing the smiles on their faces," she said. "I like to give back and I see all the other kids in the hospital and I feel bad. ... I wanted to give back to them."
The Indiana University Lilly Family School of Philanthropy also featured the art kits on its new Generosity for Life website, which tracks charitable giving and helps parents teach children about why it's important to be generous.
Amir Pasic, the school's dean, said Emma is the embodiment of the power of giving.
"It's a profound act of selflessness in the way she approaches her challenge and I think that's very inspiring," he said. "We hope that her story can help inspire others."
There is no direct-mail campaign for Emma's Art Kits. She solicits donations in person and online. Cancer Support Community's Hayes is helping to grow Emma's project.
Lori Stumpf said the community had really rallied and embraced the art kits.
"She has such a giving spirit and a wonderful spirit and she just loves to give back," Lori Stumpf said.
This report is part of the three-hour ABC Radio special, "America Gives Thanks."