Ontario’s top court’s formally acquitted a mother, who pleaded guilty 25 years ago, to killing her three-year-old stepdaughter.

The Court of Appeal took just minutes to render its decision in favour of 46-year-old Maria Shepherd.

She pleaded guilty in 1992 to manslaughter in the death of Kasandra Shepherd after evidence from now disgraced pathologist Charles Smith.

Lawyer James Lockyer of the Association in Defence of the Wrongly Convicted told the province’s top court that other experts have now concluded Smith’s opinion was seriously flawed.

Her lawyer at the time consulted an outside expert who agreed Smith’s theory was reasonable, prompting her to plead guilty.

She was sentenced to two years less a day.

Crown Attorney Howard Leibovich said there’d been a ”miscarriage of justice, and that Shepherd would not have pleaded guilty had she known then what she knows know.

The theory now is that Kasandra may have had a previous brain injury that caused seizures or that she suddenly developed a seizure disorder that killed her.

Speaking outside Osgoode Hall, Shepherd said she was ”elated” by the decision after having the label of ”baby killer” hang over her head for more than two decades.

Smith’s autopsy was one of many suspicious child deaths he had done, several leading to wrongful convictions.

He lost his medical licence in 2011.