City police said Krystal Nichols has been located.
The 33-year-old was reported missing on Tuesday, but has since been found.
Sarnia police thank the public for their help in the matter.
While a cashier was scanning items, the man reportedly took out a firearm and demanded that they put the items into a brown paper bag.
Police are appealing for witnesses or dashcam footage
Lambton County OPP say the investigation is continuing
Point Edward virtuoso harmonica player Mike Stevens is among 83 people appointed to the prestigious Order of Canada.
Canada Day festivities are planned for Tuesday in Petrolia, Forest, Port Franks and Grand Bend.
Shortly after 6 p.m. Sunday, Sarnia police responded to reports of a man walking into traffic on Christina Street near Wellington Street, and threatening random people on the sidewalk.