According to Skate Canada officials, Therese Rochette was taken to hospital on Sunday morning and had died of a heart attack. She was 55.
"Her mother arrived yesterday and died early this morning," Barb MacDonald said. "She was informed of the news by her dad and coach at 6 a.m. this morning. Joannie is understandably in shock but she plans to compete here."
Rochette had already been tipped as the only athlete likely to stop an Asian sweep of the medals in the women's competition following her silver-medal performance at last year's world championships.
The 24-year-old Rochette did not attend Sunday's draw at the Pacific Coliseum but did arrive later for her 40 minute practice session. She was drawn to skate 26th out of 30 competitors in Tuesday's short programme.
Her fellow competitors rallied around her after hearing about the tragedy.
"I heard about it just before I went to practice and I felt really sorry about it and hope she gets through it and back into competition," South Korean gold medal favourite Kim Yuna said.
Yuna's coach, Canadian Brian Orser, knew Rochette's mother well and added: "I'm in shock by it. I can't imagine what Joannie is going through. I know she'll find strength and courage from her friends, coach and millions of fans."
US champion Rachael Flatt said: "It's really unfortunate, I can't imagine what it's like to lose a parent... especially when you're trying to compete."
Her compatriot Mirai Nagasu was stunned to hear the news when informed by reporters.
"Wow," said Nagasu, blinking back tears. "I think this will spur her on to do even better because here she will skate for her mum."
The 16-year-old Nagasu revealed why the news had hit a raw nerve.
"If it was me it would give me motivation as it has since my mum has thyroid cancer," she said. "I'm hoping that she'll be able to pull through and she's been really strong for me so I want to skate for my mum here as well.