"She said, 'Dad, I don't want anyone to know, but I would do this for free,'" said Dayna's father, Brian Less.
Dayna Less' life and career were tragically cut short Monday when she was shot while getting off an elevator at Mercy Hospital, where she was in her first year of residency.
RELATED: What we know about the gunman at Mercy Hospital
Brian Less is adamant that his daughter, his only child, not be remembered as a victim. Instead, he wants her to be remembered for how she lived.
"She was the best and brightest star on this planet and she didn't deserve what she got," he said. "Dayna was a very special person. She had unique gifts. She was intelligent. She was funny. She was kind. She was a good friend."
Brian Less called Monday "an impossible day for all of us," including police officers, Mercy Hospital and Dr. Tamara O'Neal, the other civilian victim of the shooting.
WATCH: Families, hospital staff mourn the loss of Dr. Tamara O'Neal and pharmacy resident Dayna Less
Dayna, 24, was a first-year pharmacy resident who began her clinical rotations at Mercy in July. The hospital said its pharmacy residencies are very competitive, as Dayna Less was one of two pharmacy residents at Mercy, out of about 40 pharmacists who applied. She planned to do a second year residency in ambulatory care and eventually hoped to work in an outpatient care clinic, according to a press release from the hospital.
"She was very sharp and motivated, and kept everyone on their toes," said Steven Silverstein, director of pharmacy at Mercy Hospital.
Dayna Less graduated with a doctor of pharmacy degree from Purdue University just last May. Originally from St. John, Indiana, she was planning to go home on Tuesday to be with her family for Thanksgiving.
"I was going to be giving a wedding speech instead of a eulogy," Brian Less said.
WATCH: Dayna Less' father shares memories of his daughter
Brian Less remembered how his daughter overcame that debilitating headache disorder, sharing the experience of enduring pain and several surgeries in a blog in hopes of helping others.
She started a blog with her mother called "My Daughter's Headache."
While in college, Dayna served at a clinic in Kenya during a doctor's strike. Her father said Dayna truly lived to help others.
"She's helped hundreds of children across the country and internationally who are afflicted with this disorder," her father said. "She gave them hope, she gave them help and she was a friend to them. And some of them didn't make it, but she soldiered on and she helped everyone she could and she was continuing to help everyone she could in her life."
Dayna's experience as a patient inspired her to pursue medicine.
"And Dayna decided at 16 years old that she had been given her chance at life back and she was going to freely give of her life to everyone she could," he said.
Dayna Less was also engaged to be married next summer to her high school sweetheart; a man she had met at church camp when they were just 9 years old. Her mother, a seamstress, was making her wedding dress.
Amid the despair, Brian Less prayed for healing.
"Hug your kids every day. Talk to them every day," he said. "Do something every day to make their world a better place."
Mercy Hospital has created a fund to support the families of both O'Neal and Less. Click here for more information.