"I thought I may as well give it a go since I've turned 50 - I'm unlikely to get another chance."
Whanganui health care provider Te Oranganui stepped in and assisted with her Inspire Gym membership and some running gear allowing Marshall to begin training.
"This will be my first marathon and growing up I wasn't really into any serious athletics, but I'm determined. I have a son who takes me to the gym and have help from others when I train. Kylie Osborne from Te Oranganui helped organise Inspire Gym membership and Jimmy (Hildreth) from Sport Whanganui (and Wanganui Harriers Club) has been helping me with my running."
Marshall has split her fourth year of social work study to allow for the trip to Hawaii. She flies to Auckland to link up with a Doug Healey-led group also tackling the Honolulu Marathon.
Healey is a well-known fitness programme designer who also led a group to the Great Wall Marathon in June that included Whanganui woman Paula Johnson.
"There is nobody else from Whanganui going that I know of. I fly up to Auckland on December 6 and link in with Doug Healey's group. The marathon is on December 10 and we fly back on December 13," Marshall said.
In between training, study and grand mother duties, Marshall has been busy fundraising for her trip.
"I have done four sausage sizzles at Mitre 10 Mega, sold raffle tickets and I've even sold my two Lazy Boys to raise funds. I've paid $4100 for a holiday package, but I still need money for living costs while I'm over there. I'm not sure what food will cost and I'm unsure about the tipping rules over in Hawaii."
Marshall is open to any generous donations to her cause and has set up Sharon's Progress Page: Hawaii Marathon Dec 2017 on facebook to document her progress https://www.facebook.com/groups/372343413118160/