She went to the post office to mail a package to her daughter in college when she got pinned underneath the SUV and died.
One of Keagan's daughters told KHOU 11 News that she and her mom were extremely close.
"I just love her. She's the best person I know," Melody Celedon. "She's who I talk to every day. Like I text her about everything"
Celedon said she suspected the victim may have been her mom after she heard on the news what happened and remembered her sister mentioning their mom was mailing a package.
"I just knew something was wrong,” said Celedon.
Both daughters are in college and said their single mom was funny, quirky and worked hard to help support them.
"She's in a better place and I know she’s still here," said Celedon. "We miss her.”
The post office remained closed Thursday as the investigation into the crash continues.
Houston Police believe the 84-year-old driver was parking in a handicapped spot and accidentally hit the gas instead of the brake, causing her SUV to drive right through the front door. The vehicle then slammed into an interior wall inside the lobby before hitting Keagan.
Police said the driver showed no signs of impairment. Her driving record is part of the investigation.
"We are going to turn over every stone," said Sean Teare with Harris County's Vehicular Crimes Division. "We are going to look at every single thing involved in this to ensure that it was exactly what it looks like, a tragic accident."
Coincidentally, she and Keagan lived in the same neighborhood.
If you would like to help, the Keagan family has sent up a GoFundMe.