Rehab Dughmosh, 32, was charged with 14 counts of terrorism-related offences, a month after allegedly threatening store employees with a knife.
While in a Toronto court facing assault charges related to the incident, Ms Dughmosh declared her support for IS.
Most of the terrorism charges are related to that alleged assault on employees of a Canadian Tire store.
In June, Ms Dughmosh allegedly threatened employees of the Toronto-area branch with a knife, injuring one person. She was charged with two counts of assault with a weapon, assault, uttering threats, carrying a concealed weapon, and two counts of possession of a weapon.
When she appeared in court to face those charges, she pledged her allegiance to the leader of IS, telling the court: “I am pledged to the leaders of the believers, Abu Bakr al-Baghdadi.”
Prosecutors now believe the assault was motivated by terrorism, and 13 of the 14 charges relate to that incident.
One additional charge alleges Ms Dughmosh travelled to Turkey in April 2016 and attempted to enter Syria to participate in terrorist activity.