Annaleise Carr of Walsh, Ontario, stroked her way 52.5 kilometers (about 32.5 miles) from Niagara-on-the-Lake to Toronto's Marilyn Bell Park, reaching the shore about 9 p.m. after 27 hours in the water, the Toronto Star reported.
A large crowd cheered her when she reached the park, named for Marilyn Bell, who was 16 when she swam the lake in 1954.
Annaleise, who raised the money for Camp Trillium, a summer camp for children with cancer, battled strong winds, cold water and swells more than 3 feet high during her swim
Her coach, Lisa Anderson, said the young swimmer didn't show any signs of distress.
Annaleise was given water and food delivered by tether and a lacrosse stick, the Star said, since she was not allowed to touch any boats during her swim.
Another 14-year-old, Natalie Lambert of Sydenham, Ontario, completed a different trans-lake route, from Sackets Harbor, N.Y., to Confederation Basin in Kingston, in 2007, the newspaper said.