For someone who witnessed first-hand the fitful starts and stops women's hockey endured in establishing its foothold as a professional North American sport, the 37-year-old Marvin leaves the game in a better place.
"Every time, I kid you not, I stepped on the ice I was almost moved to tears," Marvin told The Associated Press ahead of her announcement.
"And a couple of times I was moved to tears just watching the fans, watching my teammates, seeing the little girls pounding on the glass. And I'm like, `This is the coolest experience,'" she added of her season with PWHL Boston. "This is what we fought for for so long. ... And there's so many people to thank."
Marvin got her start in the northern Minnesota community of Warroad, where her grandfather helped establish the city's youth hockey program that went on to produce NHL players, including Washington's T.J. Oshie, and Olympians.
She played her college hockey at Minnesota, where Marvin was a two-time national MVP finalist, and that helped lead to a 12-year stint on the U.S. national team. Along the way came five world championships, Olympic silver medals in 2010 and '14, and finally a gold in 2018.
In between, Marvin competed in three now-defunct women's pro leagues, starting with the Western Women's Hockey League, before coming out of semi-retirement to play in the PWHL.
Marvin reached the decision to retire while running her annual summer youth hockey camp following a season in which Boston lost the Walter Cup final in a decisive Game 5 to Minnesota.
The loss will always sting. But Marvin said she is at peace even while having no plans on what comes next while signing a one-day contract to retire with Boston. She's made Massachusetts her home, and has had several stints in broadcasting, which Marvin hopes to pursue further.
"I'm definitely not going out with any regrets," she said. "I had a long and fruitful career with incredible teammates and awesome coaches along the way. I feel very blessed."
Versatile enough to have played forward and defense, her favorite memories include scoring a shootout goal in the United States' 3-2 gold-medal win over Canada in 2018. The Americans rallied from a 2-1 third-period deficit and Jocelyne Lamoureux-Davidson's sixth-round shootout goal stood up after Maddie Rooney stopped Meghan Agosta on Canada's final chance.
"Nerve-wracking to watch," Marvin recalled. "You're sitting on the bench watching Jocelyne dangle and you're like, `Just score already.'"
She retired from the national team in December 2021, finishing with 24 goals and 50 assists in 126 games.
Marvin also won a Clarkson Cup with the Canadian Women's Hockey League's Boston Blades in 2013, and the inaugural Isobel Cup with the National Women's Hockey League's Boston Pride in 2016. She finished with a goal and three assists in 24 PWHL games last year.
For all Marvin accomplished, the memory that stands out most is playing in front of her family, including 7-year-old nephew Cohen, during the Walter Cup final in Minnesota.
"We played mini-sticks in the hallway of the hotel the next day, and (Cohen) didn't want to be any other goalie except for Aerin Frankel," Marvin said, referring to Boston's netminder.
"It was so cool that not only can girls grow up and want to see the model in front of them, but you have incredible athletes who young boys are recognizing for their skill," Marvin added. "Those are some of different things that came to mind that would never have happened had we not had the Professional Women's Hockey League."