A pregnant farm worker delivering vegetables to a Big Apple market was killed Saturday, and her 14-year-old stepdaughter was clinging to life after a horrific accident in the Bronx, police and relatives said.

Jennifer Parisella, 30 — driving a 2003 Ford Econoline van — was pronounced dead at the scene after she rear-ended the 2014 Volvo Tractor on the Major Deegan Expressway near Brook Avenue just before 7 a.m., cops said.

Her 14-year-old stepdaughter, Sky Mendoza, who was sitting in the backseat was rushed to Lincoln Medical Center in critical condition. Her 12-year-old stepson, Orlando Mendoza, Jr., who was also in the back seat, was taken to Jacobi Medical Center in stable condition with body trauma, according to cops and relatives.

A 28-year-old man riding in the front passenger seat, who a relative identified as the victim’s brother, was taken to Lincoln in stable condition with a leg injury.

The family, who lives in Middletown, N.Y. and works on a farm, was on their way to the city to bring produce to a farmer’s market, said a cousin who only gave his first name, Anthony.

About a dozen people gathered at the waiting room at Lincoln Saturday afternoon — many, if not all, sobbing and hugging.

“She was five months pregnant,” said a cousin who declined to give her name. “She was excited. She was so happy. That would be her first child.”

Still, she raised both the 12-year-old — who broke his collarbone — and the 14-year-old, who was in surgery Saturday afternoon for bleeding to the brain and a broken spine.

“She has a 50-50 chance,” another cousin said of the teen girl. “Keep them in your prayers.”

The truck driver, also 30, stayed on scene, and was taken to Lincoln Medical Center in stable condition. No arrests were immediately made.

About an hour earlier, one person was critically injured in a smash-up on the westbound Long Island Expressway, near Kissena Boulevard in Kew Gardens Hills, the FDNY said. Another person was seriously hurt, and five others sustained minor injuries. All seven were taken to New York–Presbyterian Queens hospital.

And around 4:45 a.m., a tractor-trailer crashed into a divider on the eastbound Long Island Expressway near 188th Street in Queens, cops said. Three people were taken to Long Island Jewish Medical Center with minor injuries.