Sonia Petrosoniak was born and raised in Mississauga, Ontario. She played PWSA softball from Mite to Senior, playing for a few organizations including Mississauga North, Chinguacousy Cougars, Cambridge Coyotes, and Guelph Gators. She attended 10 Canadian National Championships, medalling in 6 of them.
Sonia received a scholarship to NCAA D2 California University of Pennsylvania. While there, Sonia was a pitcher, and two-time Academic All American, recording a career ERA of 1.64. In her senior year, the Vulcans ranked 14th overall and finished the season as NCAA Division II Super Regional finalists.
She graduated with a BA in International Studies and a Masters of Arts in Teaching. Sonia has taken NCCP coaching courses, and is now a teacher with the Peel District School Board.