A woman killed by stray gunfire in The Bronx was a doting mother of four whose singular mission in life was to ensure her boys became successful, the kids’ devastated dad told The Post on Saturday.

Cindy Diaz’s quick trip from her East Tremont apartment to grab dinner for her kids at a nearby McDonald’s proved fatal Friday, when she was struck at around 5:37 on Boston Road.

“She was an innocent person. All she was doing was getting food for kids,” dad Angel Rosario said through tears at Diaz’s 179th Street apartment.

“It’s horrible; it’s a travesty and all for nothing. I bet when we find out what happened, it’s going to be nonsense.”

Diaz, 48, was struck in the torso and arm and was taken to St. Barnabas Hospital but could not be saved.

Another victim, 18, was shot in the right arm.

The teen, who a source said has a record of six arrests, was believed to have been the intended target.

He was patched up at Jacobi Hospital, then hauled the 48th Precinct station house for questioning.

He was not cooperating, police sources said.

Diaz’s four boys — Liam, 15, and Takis, 14, who attend St. Raymond High School for Boys in Parkchester, and Reino, 13, and Giavanno, 11, who go to St. Raymond Elementary in East Tremont — were the light of her life.

“They got good grades. Why? She sat there with them. She used to study with them — that’s why the kids are bright.

“That was her doing,” Rosario said.

Rosario, 51, who separated from Diaz a few years ago, said the tragedy was made even more gut-wrenching because the children lost their mom on Three Kings Day, which is akin to Christmas — with gift-giving — for some Christians.

Rosario urged the gunman to turn himself in and deal with the consequences.

“I want to see justice. I want to see him pay for what he did but at the same time, of course, get help because nobody knows the stories of these kids and what’s going on in their households.”