In our "Why I'm Running" series, Boston Marathon athletes share what's inspiring them to make the 26.2-mile trek from Hopkinton to Boston. Looking for more race day content? Sign up for Boston.com's pop-up Boston Marathon newsletter.

Name: Beth McKenna

Age: 40

From: Wethersfield, Conn.

My daughter Lydia was born in the 18-month window between qualifying for my first Boston Marathon in October 2017 and the 2019 race. I was on cloud nine - I had a healthy toddler named Patrick, a beautiful new baby girl, and I was finally realizing my dream of running Boston.

However, just weeks after being notified of my acceptance, I received the news that would change our lives forever. My 10-week-old infant girl had been born with a rare condition called Neurofibromatosis Type 1 (NF1). NF1 causes tumors to grow on nerves throughout the body and can lead to blindness, learning disabilities, bone abnormalities, cancer, disfigurement, and disabling pain. There's no way to predict the severity of symptoms, and there is no cure.

After the initial gut punch and devastation, I realized that doing something (anything!) gave me hope and a sense of control over the situation. I teamed up with the Children's Tumor Foundation, an organization on a mission to #EndNF, and raised over $30,000 for CTF in tandem with my journey to the Boston starting line.

Today, Lydia is a happy, spirited 6-year-old who is also managing two brain tumors, a complex neurofibroma on the back of her head, and frequent headaches. She's stronger and fiercer than I ever could have imagined.

The 129th Boston Marathon will be my third. I continue to run to be an example of strength and grit for my children. I run for me, the challenge and achievement being a form of self-care that runners know well. And though I gained entry as a qualifier, I run this race as a platform to bring awareness and raise funds for an organization that is dedicated to improving the quality of life for my daughter and thousands of others who suffer from NF.