Neighbours reported seeing two girls, aged approximately nine and 11, run out of the fiery trailer with their hands zip-tied before being taken away by ambulance.
Mission RCMP were called to the Green Acres Park home in the 9200 block of Shook Road around 3 a.m. PT Friday following reports a trailer home had gone up in flames.
Crews, put out the fire and entered the trailer where they found Anthonysz's body inside.
One of her neighbours, who wished to remain anonymous, told CBC News she "heard a lot of screaming that sounded like it came from a female," during the fire.
Police said Saturday, Ramsey was found at another home where he was taken into custody.
He has been charged with one count of first-degree murder, two counts of attempted murder and one count of arson for allegedly setting the trailer home on fire.
"I can't imagine what these poor children have gone through," the neighbour said. "They appeared to be in shock."
Police confirm that two children were taken to hospital as a result of the incident.
Ramsey has been remanded into custody and will appear in court, Monday April 20.
"I would like to extend my sincere condolences to the family of Ms. Anthony," said Sgt. Stephanie Ashton of the Integrated Homicide Investigations Team. "[I] hope that the speed with which the alleged suspect was apprehended gives them some measure of comfort in the days ahead."