The 12-year-old Brooklyn girl killed in a Brooklyn subway surfing incident had posted terrifying daredevil TikTok videos — including one where she lay on train tracks — in the weeks leading up to her tragic death, The Post has learned.

The videos were revealed as young Zemfira Mukhtarov’s mother said her pre-teen daughter was obsessed with pulling off the social media stunts despite her parents’ pleading, and had snuck out in the middle of the night Saturday before she was killed.

“I always working, and I don’t know what she’s doing, what time she’s doing,” grieving mom Nataliya Rudenko, of Ukraine, told The Post on Monday. “One time I see she is on the top of the Williamsburg Bridge, [pretending to] hold our city on her hand.”

Rudenko, who moved to the US in 2008, said she tried to warn her out-of-control daughter that “it’s dangerous, you don’t have to do this,” but ultimately couldn’t stop her from pulling off dangerous stunts throughout the Big Apple.

Last month, Zemfira posted a TikTok video as she lay on the tracks as a subway rumbled over her, while another clip showed a young girl on a narrow beam while a train zips by underneath her.

The pre-teen was killed early Saturday morning while riding on top of a J train near the Marcy Avenue-Broadway station.

Rudenko said she came home from work to find that her thrill-seeking daughter snuck out of the house sometime before 3 a.m. while her kid sister and dad were sleeping in their Bay Ridge home.

At around 3:10 a.m., Zemfira and her 13-year-old pal, Ebba Morina of Manhattan, were found unconscious near the Williamsburg station — with both later pronounced dead.

Rudenko said her daughter had increasingly roamed the city seeking thrills, including subway stunts, sneaking into empty mansions and climbing onto the roofs of high-rises — sometimes posting the videos online.

It was a bizarre turn for a normal youngster who played volleyball in school, took martial arts and violin lessons, and even visited Disneyland with her family, her mother said.

“She’s not a kid [who] sits in her room, and I cannot close this room and take a key and just, you know, [make her] stop doing this thing,” the distraught woman said.

Rudenko said she does not know Morina and believes the two girls likely met online — with police reporting that they were among as many as 15 youngsters running around inside the train before the tragedy.

Zemfira’s mourning father, Ruslan Mukhtarov, who is from Azerbaijan and joined the family in New York at some point after Rudenko moved, posted a GoFundMe page to raise money for his daughter’s funeral and memorial service, with nearly $17,000 in donations pouring in by Tuesday.

Meanwhile, city officials continue to warn teens and youngsters to refrain from subway surfing.

The dangerous stunts, increasingly fueled by social media, killed six people last year and five in 2023 — after just five died riding atop subway trains between 2018 and 2022.