Beth Claire Smith, nee Harvey, from the Savile Park area, died in November 2020 from what was later found to be deep vein thrombosis.
She had taught at several primary schools in Halifax before joining tuition agency White Rose Maths.
Her friends have formed a group called Beth's Beavers to raise money for the baby loss charity Talkthru, as Beth and her husband Ian had suffered a miscarriage when they lost their daughter at 19 weeks.
Around 30 of them will be running the Yorkshire Marathon in York on Sunday, having already raised £15,000 from other events.
They said: "Most of us have never even run for a bus before, let alone a road race, but we’re determined to come together, have fun, and fulfil our goal in Beth’s memory.
"The aim of our fundraising is to do something just a tiny bit as incredible as Beth was, and keep building on the wonderful legacy she created.
"As a maths specialist, Beth's work with White Rose Maths genuinely changed the way maths is taught for thousands of children. And through her dedication to amateur theatre, Beth inspired and supported young people in Halifax and beyond to get on stage and achieve their dreams. We are determined her passion will live on.
"As all those who knew her will attest, Beth was generous, vivacious, energetic, as well a source of love and inspiration to so many people.
"Prior to her tragic death, Beth and her husband Ian had suffered a series of miscarriages, including the devastating loss of their daughter Poppy at 19 weeks of pregnancy. To help cope through these most difficult of times, Beth sought help from the fantastic local charity, Talkthru.
"The counsellors at Talkthru helped Beth feel positive for the future and gave her the courage to share her experiences with others. In a Facebook post sharing her experiences, she described contacting Talkthru as "the best choice I have ever made." That's why, in Beth's memory, we're raising money for this amazing charity.
"We hope that donating to Talkthru will help others who are struggling and that even after her passing, Beth will continue to bring light and hope to people's lives - just as she did in life.
"We love you Beth, and know you’ll be cheering us on as we tackle the Yorkshire Marathon Relay in your memory."
To support Beth’s Beavers and donate to TalkThru, visit Virgin Money Giving - For Beth Smith.