While loitering behind one of its Winnipeg branches with friends and clashing with authority figures who questioned her presence there, she never imagined the inside of the building would have any appeal.
But when Stranger began doing some community work, the Y soon took on a different role in her life.
Hours pushing a broom through the building soon led to involvement with one of the organization's after-school sports programs for primary school children from troubled neighbourhoods, then to a month at a YMCA summer camp for at-risk youth.
Two years after furtively sneaking onto the grounds, Stranger now walks through the front door after school to teach children how to use the Y's climbing wall.
The extracurricular programs that have filled her leisure hours during those years, she says, have almost single-handedly saved her from the influence of peers who were leading her down a dangerous path.
"If I had activities to do, I don't think I would have gotten involved in any of that," Stranger, 17, said in a telephone interview. "I would have met more people that were good for me and weren't involved in that stuff to begin with."
Stranger was the beneficiary of the YMCA's youth outreach strategy, which the organization describes as the hidden face of its operations.
YMCA Canada chief executive Scott Haldane said more than two million children and young adults walked through the Y's doors last year to take part in the organization's array of youth programs, adding the figure has soared by up to eight per cent in the past decade.
The fitness and recreation facilities that have given the Y nationwide brand recognition barely touch on the complex needs of the young people the organization serves, he said.
After-school childcare, youth employment training seminars, language skills classes for new young immigrants, after-school leadership courses and summer camp programs all fall under the auspices of the organization's youth strategy, he said.
"Research demonstrates that many of the factors that influence whether you're going to live a healthy life have to do with things like your income level, your education level, your social network. They don't have to do with things like hospitals and doctors," Haldane said.
"One of the things we've done is really realized that if we're going to have an overall impact on the health of children of Canada, which frankly doesn't score very well, we have to help low-income people have access to programs and reach out to make sure that education and recreational opportunities are there."
Haldane said the organization picks up the tab for at least a quarter of its youth participants, who often come from troubled circumstances and lack the financial resources to take part without help. A current campaign to raise $10 million, he said, would allow the organization to keep pace with rising demand and hopefully expand to more remote communities crying out for relief.
Tahirah Stanley, 22, said such financial support helped save her from the violence that has taken a toll on her community.
On the streets of her gritty Toronto neighbourhood, Stanley said she routinely confuses the sounds of fireworks with the noise of fatal gunshots, one of which struck down a childhood friend just months ago.
The after-school programs that consumed her time as a teenager, she said, gave her the tools to offer similar resources to the community she loves in spite of its tensions.
Stanley's participation in media arts courses inspired her to start Theatre for Peace, a performing arts program currently run in partnership with the YMCA.
The three-month, after-school program gives teens the chance to explore various aspects of performance from songwriting to acting, all the while exploring social issues of the day. The program culminates in a 30-minute play put on for the community.
Stanley said participation in the arts can teach social skills that are invaluable for those hoping to escape a life of violence.
"Even if you don't want to be an actor, I think everyone should take a theatre course. It teaches you how to express yourself, teaches you confidence and all those things," she said.
"When you're on stage, you're forcing someone out of their comfort zone. It's also what being outdoors and going on canoe trips does, and also being away from your family."
Wilderness adventures proved a turning point for Stranger, who initially resisted the notion of leaving the community where she felt most at home.
One prolonged canoe trip, however, made her question what else lay beyond the city limits.
"It was the scenery, most of it. It was absolutely gorgeous," she said. "Canoeing for 10 days, all you see is trees, rocks, stuff you don't get to experience in the city at all."
Stranger said the alternatives she's explored through her involvement with the Y have instilled a commitment to helping younger children avoid the path she nearly travelled.
"It's pretty crazy. It makes me feel good, though, that I get to be there for those kids."
Note to readers: This is a corrected story. A previous version misspelled the surname of YMCA Canada chief executive Scott Haldane.