Garnering critical acclaim for her performance as Elizabeth Shoaf in Lifetime's 2018 TV movie Girl in the Bunker, Lalonde was previously well known for portraying Diana Barry in the Anne of Green Gables TV movie trilogy. She also played Agent Octavia in Odd Squad.
She debuted on television in 2010 as part of the documentary series Ghostly Encounters.
She was a guest-star in a 2014 episode of the show Heartland.
She was born in Toronto, Canada. Her father's name is Christopher Lalonde.
She starred alongside Henry Thomas in Girl in the Bunker.