A Long Island woman was arrested for murder Tuesday — after she called the cops to report that she’d strangled her 76-year-old mother to death, police said.

Sharon Easter, 57, of Central Islip, allegedly confessed to choking her mother with the cord of a vacuum cleaner to a 911 operator at about 8 a.m., Suffolk County Police said.

“She was very matter of fact. She said she just killed her mother,” said Detective Lt. Kevin Beyrer of the Suffolk County Police homicide unit.

When cops got to the home on Cocoanut Street near Islip Avenue, they said a still “very matter of fact” Easter answered and pointed them to the body of her mother, Dorothy Easter, who died of strangulation wounds.

Police believe Easter was upset over the passing of her father, who died of natural causes, and “mistakenly blamed the mother,” Beyrer said.

Relatives told The Post they were shocked.

“I’m just trying to get over it, I’m trying to cope with it,” said Sharon’s brother, Darryl Easter, when reached by phone.

Sharon was charged with murder in the second degree. She is scheduled to be arraigned at First District Court in Central Islip on Wednesday.