Dr Stevenson is a member of the Avon Valley 10th Light Horse Memorial Troop, a small group of riders devoted to preserving the history and tradition of the regiment.
Dozens of accomplished riders from the Wheatbelt volunteered to serve in WWI, with many joining the 10th, WA's only light horse regiment.
For many, that first trip overseas was their last - and those who returned home had witnessed unspeakable slaughter.
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READ NOWDr Stevenson said she felt privileged to accept the invitation from the York Returned and Services League to lead the march in her new hometown.
"I recently moved to York and this is an honour," Ms Stevenson said.
"I have the uniform, an original saddle and one of my patients loaned me an old belt that belonged to the light horse."
Dr Stevenson said thousands of horses were shot in WWI.
"Our boys were forced to destroy their mounts in Egypt; only two horses made it home," Dr Stevenson said.
Phil Sullivan, who helped establish the Avon Valley 10th Light Horse Memorial Troop in 2001, will lead the Anzac Day march in Northam, alongside Kevin Williams and 16-year-old Bailey Pinazza.
Throughout the year, Mr Sullivan, of Bakers Hill, visits hundreds of schools across WA with his light horse memorabilia display.
His collection includes a full-size horse model and a Light Horse trooper mannequin, together with more than 1800 photographs.
"The Light Horse has been a passion of mine for many years and we are keen to hear from anyone wanting to join the Avon Valley troop," Mr Sullivan said.
In 2012, he participated in a re-enactment tour across Israel and Turkey involving visits to historic battles and joining in flag ceremonies.
Schools and organisations interested in Mr Sullivan's historic collection are invited to email philmaur@bigpond.com or call 0417 182 998.
York Anzac Day March:
From 5am, three shuttle buses from York cemetery to Mt Brown for 6.30am dawn service with piper, breakfast at RSL Hall.
10.30am form up for 10.45am march to York War Memorial with Kalamunda District Pipe Band for 11am service, lunch at RSL Hall.
Gold coin donation.