The grieving mother of a young girl killed by MS-13 gang members on Long Island was fatally struck by a car on Friday while preparing for a candlelight vigil at her daughter’s memorial, cops said.

Evelyn Rodriguez — who attended President Trump’s State of the Union Address to shed light on the brutal slaying of 16-year-old Kayla Cuevas — was struck by a vehicle in Brentwood at around 4 p.m. — two years to the day her daughter’s body was found in a wooded area off the same block, according to police.

“My thoughts and prayers are with Evelyn Rodriguez this evening, along with her family and friends. #RIPEvelyn,” Trump tweeted Friday.

Rodriguez, 50, was on Ray Court — near where the remains of Kayla and her best friend Nisa Mickens, 15, were found. The two had been beaten with baseball bats and hacked with a machete by MS-13 gang members.

The mom was preparing for the vigil when she and a woman driving a white 2016 Nissan Rogue got into a heated altercation over a memorial for the two girls that had been dismantled in front of a house on the block, cops said.

The woman was a relative of someone who lived at the home, according to police.

In video footage posted on Long Island News 12’s Web site, Rodriguez and a man can be seen confronting the driver.

That’s when the SUV driver accelerated and fatally struck Rodriguez, cops said. The network did not air that part of the footage.

Rodriguez was rushed to Southside Hospital in Bay Shore, where she died.

The driver remained on the scene and called 911. She was not arrested on Friday night, but Suffolk County Police said that its homicide squad was investigating the incident.

Rodriguez was a fierce advocate in the crusade to eradicate gangs. She urged schools to do more to combat gang-related violence, a pervasive problem on Long Island, where MS-13 has been responsible for at least 25 murders since 2016.

She was placed in the national spotlight last January when she attended Trump’s State of the Union Address.

“I just want what’s right to be done,” Rodriguez had told The New York Times in advance of the event.

“Everybody should put their political agenda aside and think about what’s going on in our country.”