After being woken up in the middle of the night by the storm, Flake checked her Facebook and was overwhelmed by images of the devastation.
And the flooding near the San Marcos nursing home where her mother Dixie battled early on-set Alzheimer's until her death in 2013, really struck the young mother.
"Having a 1-year-old and a 3-year-old, it's hard for me to get down there and volunteer in person," Flake tells PEOPLE. "And I thought, 'Maybe I can make a shirt,' because I knew people were selling T-shirts, but none of them were very feminine-looking."
Flake says she wanted to make 'Texas Strong' T-shirts for women, as she has been teaching her young daughters that strong is beautiful.
"My 3-year-old is very into superheroes," Flake says. "But she tells me all the time that she's not pretty, so lately our motto has been 'Pretty Strong' – because girls can be both beautiful and strong."
Flake used a platform called Teespring to design flattering "Texas Strong" women's T-shirts she could sell to raise money for the flood victims. At the last minute, she decided to add a tribute to her mother by including the phrase "love of dixie" on the back of the shirts.
Flake hoped the shirts would allow her to give back to the community that gave her mom so much.
"My goal was to sell 50 shirts, which would have raised a few hundred dollars for disaster relief in San Marcos, where my mom spent the final years of her life," she says.
Within 24 hours, the shirts raised $10,000. By Wednesday, the amount topped $55,000 – a figure she calls "just crazy."
One hundred percent of the profits are going to the United Way of Hays County Disaster Relief Fund to help flood victims in Hays and Caldwell counties. Flake has now set a goal to raise $100,000.
"It's overwhelming, almost, the amount of support that T-shirt has raised," Michelle Harper, CEO of United Way of Hays County, tells PEOPLE. "The outpouring of love that we've seen not only for her T-shirt but our community is amazing."
Flake says she and her brother are looking forward to seeing their mother's name "on a whole lot of backs around here."
The proud Texan has received countless messages of support from her community, but she says one phrase keeps coming up: "Your mom is smiling down on you."
You can purchase a shirt here.