A pregnant 34-year-old Brooklyn woman walking home with her child from school was fatally shot as she bravely shielded hers and other children when gunfire erupted on a Brownsville street today.

Bullets also struck an 11-year-old girl and a 31-year-old woman who was walking out of P.S./I.S. 298 with her own kids right after dismissal at about 2:35 p.m., authorities said.

“As soon as we crossed the street, they started shooting,” said a cousin of the dead woman Zurana Horton, a mother of 13 kids who was on the way to pick up another one of them from another school when she was struck down.

“The gunfire was everywhere, we couldn’t move, there was nowhere go, we didn’t know where the bullets were coming from,” said the cousin, who did not give her name. “She was about to get ready to move out of here, she’s getting married, but now she can’t do any of that.”

As Horton lay dead on the street, one of her kids who had not been there during the shooting walked by her — and didn’t recognize her because her face had been wrecked by a bullet, a relative said.

And the 11-year-old victim, Cheanne McKnight, “kept screaming, ‘They shot me in the face! They shot my face!’” said her aunt Ximinia Fernandez.

“I didn’t know if she was OK — I just saw a big hole in her face,” Fernandez said at Brookdale Hospital, where she drove her niece after the horrific shooting. “That poor little girl.”

Cheanne was in stable condition with a graze wound to her face.

The shots — believed to have been fired from the roof of a nearby building — struck the victims as they walked in front of the Lucky Supermarket on Watkins Street, less than a block from the school, police said.

NYPD spokesman Paul Brown said cops are eyeing the possibility that the gunman was firing at a group of youths arguing on the street below. Cops retrieved seven 9mm shell casings from the rooftop of the building at 1800 Pitkin Avenue — a gang-ridden address — and another five 9mm casings from the sidewalk right in front of the building.

A witness, Jay Williams, 45, told The Post that argument came when “kids were throwing rocks kids were throwing rocks at this guy. He told them to stop,” Williams said. “Next thing you know . . . [there were] several shots.”

When Horton heard the gunshots, she grabbed the child she was with and others around her “to protect them as the shots were fired,” Browne said.

Her dramatic sacrifice was caught on a surveillance video, sources said.

Maxine Thompson, 45, who lives nearby, said, when she walked outside she saw Hortin with “bullet wounds to her face, her face was torn off,” Thompson said.

Horton’s children ranged in age from 1 to 15, according to relatives.

The third victim was identified by a cousin as Unique Mobily, who was shot in the arm and chest as she walked from the school with her kids.

“She says she’s OK, I talked to her,” said Mobily’s cousin, who did not give his name. “She’s in pain, she’s hurting.”

“She had her two little babies with her.”

Cheanne’s mom, Harriet McKnight, said, “I got a call . . . my daughter was shot,” said “I was hysterical . . . I thought my daughter was dead.”

“I want to kill the person that shot her. If anybody knows something, come forward,” McKnight said.

Three men, one with a black hoody and a second in dark clothing, fled from the scene eastbound on foot on Pitkin Avenue and entered 1801 Pitkin Avenue, said Browne, the police spokesman. One person was being questioned by cops there last night.

Two people inside 1800 Pitkin Avenue were being questioned, Browne said.

Two suspects, including the gunman, were still being sought.

“This area’s a high-crime area, especially at night and during school,” said Thompson, the neighbor. “They don’t care about no school here.”

“It’s crazy.”

A $12,000 reward is being offered for information in the case.

Additional reporting by Ikimulisa Livingston, Jessica Simeone, Andy Campbell, Frank Rosario and Yoav Gonen