The mother of the crazed Queens woman who killed a new mom and seriously wounded an elderly dad in a terrifying Times Square stabbing spree is questioning why cops didn’t just “grab” her daughter rather than fatally shoot her when she charged at them with knives.

Pamela Cisneros, 49, stabbed Erin Piacenti, 32, and Tak Kam, 68, Monday afternoon before cell phone video showed her being surrounded by police and threatening to kill them with a large knife in each hand.

NYPD officers attempted to deploy tasers, but they were ineffective. She then rushed at them while waving the knives, prompting two officers to open fire, the dramatic footage shows.

“There were so many police… why didn’t they grab her by the arm?” Cisneros’ mother, who did not give her name, asked Fox 5 News in Spanish.

Cisneros, a mother of three, was later pronounced dead at Bellevue Hospital.  

Cisneros suffers from what her brother described to The Post Tuesday as bipolar disorder, but said she’d been receiving treatment in recent years and “never showed any aggressiveness.”

“I don’t know what happened,” Patrick Peralta, 59, said, adding his sister had found some stability through medication in recent years and reported feeling “fine” as recently as Saturday.

Cisneros, of Queens, had a documented mental health history with police, including a suicide attempt.

Cisneros drew the attention from NYPD cops in December 2018 when she was belligerent, intoxicated and screaming along Lexington Avenue, sources said. She then tried to kill herself in March 2019 by jumping in front of an E train in Queens, sources said.

Court records show that Cisneros’ marriage fell apart around this time, with her husband filing for divorce in Hillsborough County, Florida, during 2020. The divorce was finalized last year.

The unprovoked stabbings and subsequent shooting all happened within a roughly 20-minute window beginning around 4:30 p.m. Monday and sent panicked tourists and commuters running for safety.

Cisneros had whipped out two knives from a red Target bag and stabbed the first victim, Tak Kam, a 68-year-old dad from Rhode Island, in the abdomen as he exited the subway on West 41st Street and was waiting to cross the street, police said.

She then continued up to 42nd Street and seconds later fatally stabbed Piacenti — a vice president at Bank of America who had just returned from maternity leave.

The slain new mom from Chester, NJ, had posted a touching photo just four days before her murder of herself smiling broadly while holding her infant and standing with her husband. She wrote in the caption how happy she was.

The baby had recently been baptized and Piacenti and her husband, whom she just celebrated her second wedding anniversary with, had been taking her time off to travel.