A heroic Indiana mother was killed when she stepped in between her son and an 18-year-old gunman who had pulled a firearm on them during a Facebook marketplace sale.

Jean Gragg, 40, and her teenage son were selling a watch to prospective buyer John Ford during an arranged meet-up on the front porch of their Edison Park, Ind., home near the University of Notre Dame on June 10, South Bend Police said.

Gragg’s son had planned to sell the watch to Ford just before 10 p.m.

Family friends said the exchange was common for Gragg’s son, who has made sales through Facebook Marketplace “many times before.”

Ford allegedly pulled out a handgun while he was inspecting the timepiece.

“When Jean stepped in to support her son, the man went over the edge,” family friend Debra McKinley wrote on a GoFundMe.

Gragg, an office manager for H&R Block, wedged herself between the two teens and pushed the suspected gunman away and off her property.

Ford allegedly fired multiple shots at Gragg, who was walking up her driveway back to her home as her horrified family watched.

She was struck in the head by one of the rounds.

Nearby security cameras captured Gragg falling to the ground as Ford ran away, according to court records viewed by WSBT.

Gragg was rushed to a local hospital in critical condition before she was declared brain-dead. She was taken off life support by 6 p.m. on June 13, McKinley said.

“My superhero,” Gragg’s son told WNDU.

Gragg was remembered as a traveler who enjoyed spending time with her son and friends.

“She was a nurturer, if anyone close to her was sick, you could count on her to take excellent care of you,” her family said in an online obituary. “Jean was a dedicated, wonderful mother, very loving and caring, always putting her son first down to her very last breath. (He) was her whole world.”

Ford was tracked down to an apartment complex 2 miles from the scene of the shooting.

Police had also found the suspected gun dumped over a fence at the complex.

Ford allegedly admitted to shooting at Gragg during an interview with police.

He has been charged with murder, attempted murder and robbery in the shooting.

Ford is being held at the St. Joseph County Jail without bond, according to police.