Kayleigh Williamson has crossed the finish line at the Austin Half Marathon three times. Each time she's cut an hour off her time and now runs about an 18-minute mile.

She's working toward some big goals: Run the Detroit Free Press International Half Marathon in Detroit and Windsor, Ontario, in October and run a full Austin Marathon by 2021.

Williamson, 29, has Down syndrome. She's been running for her health but also to raise awareness about what people with Down syndrome can do. For each race, she's had to qualify just like everyone else.

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This year she's written a children's book about her life and her love of running and swimming, "It's Cool To Be Me" (EnGedi Publishing). She'll have a reading and signing party on Thursday at Fleet Feet Austin, as part of the store's first anniversary party.

She's dedicated the book to people with Alzheimer's disease, which her grandmother has and which often occurs in people with Down syndrome.

"I want to run in honor of my grandmother," she says. "My grandmother is so special to me. When I was born, she always took care of me in the nursery room."

Williamson was born a month early, and her grandmother was one of the first people who held Kayleigh, says her mother, Sandy Williamson.

The story of her grandmother holding her in the hospital is part of Kayleigh Williamson's life story. It's a life story her mother has shared with her daughter through both conversations and a journal she kept.

"I was not raised as a self-confident person," Sandy Williamson says. "It's the one thing I wanted to raise her with .... to be empowered with who she is even down to Down syndrome. I never raised her that Down syndrome is a reason not to try something."

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Kayleigh Williamson wrote her story for the book using pen and paper. Illustrator Amanda Zappler did the illustrations, and Sandy Williamson helped find a publisher and shepherded the project. The book sells on Amazon for $15 and at events for a $20 suggested donation. All the proceeds go to Kayleigh's Club, a nonprofit group the Williamsons started to help encourage families of people with disabilities to get up and run.

"We may not be able to prevent everything, but a healthy lifestyle will prevent some things," Sandy Williamson says. Since they started training more than three years ago, they have cut out processed foods and artificial sweeteners, gone to organic fruits and vegetables and lost weight.

"I can see the impact on her," Sandy Williamson says. A doctor who saw her at a high of 210 pounds had expressed a fear that Sandy Williamson knew in her heart: "He said, 'This is not going to end well for her,'" she says. "It probably wouldn't have if we hadn't made changes."

Since starting running and adopting healthy habits, Kayleigh Williamson is no longer prediabetic, is in remission for some autoimmune diseases and doesn't have sleep apnea.

Kayleigh Williamson trains in the gym and swims two days a week and does short runs three days a week and longer runs on the weekends. She likes to listen to music and run in shorts, a tank top and fun compression socks such as ones with cats chasing goldfish.

When she runs locally, she wears a RunLab shirt for the clinic that has helped her train and work on building up the lack of muscle tone that people with Down syndrome have. When she runs elsewhere, she wears a National Down Syndrome Society Athlete Ambassador shirt. The Austin running community has embraced Kayleigh and been the village the family needed, Sandy Williamson says.

Related: Camp teaches kids with Down syndrome, autism to ride a bike

"I like running because I want to see my best friend William at the finish line," Kayleigh Williamson says. William is William Dyson of High Five Events, which puts on races. He is often at the finish line to put the medal around Kayleigh. 

It's Dyson on the book's front cover running with Williamson, but her mom is the one who does all the races with her from the start of training to the finish line. That's not lost on Kayleigh Williamson.

"I saw my mom, the two of us crying in tears, it tells me that I am so proud of you," she says.

Kayleigh Williamson thinks people with Down syndrome will like the book, but really it's a book for any kid, especially kids who are looked at as different.

Williamson writes in the book: "The moment my mom saw me, she told the doctors that I was going to achieve things that proved them wrong. When some kids made fun of me in school, she would hug me and tell me they just did not understand how amazing I was."

She is thinking about a second book. This one might be about her dogs, Zach and Ally, who have died, and her current Chiweenie Maggie Mae.

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