PHILADELPHIA (CBS) – The Boyle family knows far too well the meaning of service and sacrifice.

Four Boyles have dedicated a total of more than 75 years to Philadelphia’s Police Department.

One, Officer Danny Boyle, was gunned down in the line of duty in February, 1991.

But now, another member of the Boyle family is writing a new lesson in courage at Sunday’s Philadelphia Marathon.

40-year-old Kathleen Boyle, mother of 3 children, will run the marathon in her brother’s name.

The challenge of the 26-mile race made even more daunting because Kathleen is legally blind, following a burst aneurysm in her brain.

With the assistance of a guide runner, Kathleen will take on the race.

For her courage, she was presented the first ever “High Five Award” by Mayor Michael Nutter at a ceremony Friday afternoon.

While many runners will be paying close attention to their starting and finish times, along with their positions, for Boyle, only 4 numbers matter:5459, the number of the badge worn by her brother, officer Danny Boyle.

Kathleen’s dad, Pat, a retired officer, along with her mom, other family members and her children will be there to cheer her on.

Reported By: Walt Hunter, CBS 3