The woman from the Red Sucker Lake First Nation says she wants to enter the race to succeed Les Harper, who recently resigned as the community's chief.
But the Grade 4 teacher said band office staff told her that under new election rules, anyone who is married and not living with their spouse is not eligible to be a candidate for chief.
"I went to the band office, and that's what they told me — that I couldn't run for the chief because I'm not living with my husband," she told CBC News on Monday.
Spence said no one could provide her with any documentation related to the new election rules. As well, she believes community members were not consulted before the rules came into effect
"I should have that right to run because I'm a human being, and I'm a member of the band," she said.
The Red Sucker Lake First Nation has a unique set of election rules, but it's not the only First Nation with unusual restrictions over who can run.
The Garden Hill First Nation, also in Manitoba, says only those over the age of 50 can run for chief. As well, it bans anyone in common-law relationships from running.
Grand Chief David Harper of Manitoba Keewatinowi Okimakanak, an organization representing 30 First Nations in northern Manitoba, said there's nothing anyone can do but respect the community's wishes.
"Marriage is a very sacred thing in that particular community, and that is what they're trying to promote," he said.
No one from the Red Sucker Lake First Nation wanted to comment on the case.
However, CBC News confirmed that the rule changes were allowed under a "band custom" system that allows First Nations to implement their own election codes.
Many First Nations have custom codes
There are generally two ways a First Nation can elect a chief and council: through the federal Indian Act or through a band custom code, said Jacqueline Romanow, an associate professor in indigenous studies at the University of Winnipeg.
"The Indian Act has regulations about who can run for chief and council, how long terms are, electoral processes, making sure that everyone gets the vote, these kinds of things," she explained.
"But there is a clause where bands can implement their own code and go under sort of band custom. And actually, the majority of bands in Canada have some form of band custom, so that means that the individual community will determine their own election code."
Romanow said Canada's Charter of Rights and Freedoms does apply on First Nations, but it can make exceptions for aboriginal rights.
"Once a band is under custom, if there is a dispute over a regulation, Indian Affairs doesn't mediate. It has no authority under that system," she said.
"If a band member wants to argue against or dispute a provision of the code, they actually have to go to Federal Court to do that if there's no … process available within the community."
Spence said she is inspired to fight the election rule by her late brother, well-known aboriginal leader Elijah Harper.
"My brother Elijah, he never gave up," she said, "He did it for all aboriginal people, so I'm not giving up."