Gabrielle Molina, 12, hanged herself in the room she shared with her older sister, Georgina, who discovered her body at about 2:30 p.m. Wednesday.

 The devastated parents of Gabrielle Molina said the 12-year-old girl had been tormented by schoolyard bullies for months — and the abuse may be the reason she hanged herself in her Queens home.

The tragic tween’s older sister Georgia, 15, found the girl’s body about 2:30 p.m. Wednesday in their shared bedroom at their Queens Village house, their sobbing mother Glenda Molina said Thursday.

Police Commissioner Ray Kelly confirmed Thursday that Gabby left a suicide note that talked about being bullied.

Cops are investigating whether Gabrielle was a victim of online harassment as well as face-to-face abuse.

Pals of hers said Gabby got into a fistfight with another girl that was videotaped and posted on YouTube. They also said she had a history of cutting herself and had recently broken up with a boyfriend.

“There was information in the suicide note concerning cyber bullying,” Kelly said. “Detectives have taken two computers from the home and they will shortly be analyzed. It’s a terrible tragedy.”

Gabby’s fellow students at Jean Nuzzi Intermediate School 109 in Queens sent the messages currently under investigation, Kelly said.

The girl’s distraught mother said Gabby, a seventh-grader, usually drove to school with a friend’s uncle, but didn’t come downstairs as usual Wednesday morning.

“Her sister went to school. The door was locked, but that’s not unusual for her privacy,” said Glenda Molina.

Gabby’s grandparents knocked on her bedroom door periodically throughout the day but assumed she was sleeping when she didn’t respond.

When Georgia got home from school, she forced the door open with her grandmother behind her, and found her younger sister hanging there.

“I wasn’t there. I was at work when I got the call. My sister-in-law said, ‘Come quick! Gabby is …’” said the grief-stricken mother, who couldn’t finish the sentence.

Molina, a nurse’s aide, rushed home but it was too late to save her youngest child. She and her husband, George Molina, also have a 21-year-old son, a family member told the Daily News.

The parents knew Gabby had been having some trouble with bullies at school, including the fistfight earlier this spring. But the full extent of what she endured came to light only after her suicide.

“They called her a slut and a whore. All this she wrote in her journal. I just found out. I didn’t touch her journal before (the suicide). That’s personal,” the mother said.

“Her sister knew. She said, ‘Mom, she asked me to keep it secret,’” Molina said.

The mom said she learned about the bullying in conjunction with the fistfight.

“I asked how she was. She’s very honest, she told me, ‘I got into a fight.’ I asked her: Did you tell the teacher? She said, ‘Yes,’” the mother said.

“That’s when I found out she was being bullied. The girl in the fight, she was a friend. She had come here to work on projects with Gabby. That was her classmate,” she said.

A boy took video of the fight and posted it on YouTube, Molina said. It was called “Gabby’s Fight.”

According to Gabby’s family, a teacher from IS 109 called the house after the fight and set up an appointment for the family to meet with the guidance counselor and dean.

The teacher reported the YouTube video to the school, Molina said, but it wasn’t immediately removed from the Internet.

The school guidance counselor was sympathetic to Gabrielle’s plight, the mother added, and the two girls who fought made up the next day.

Gabby’s distraught dad was at a loss to explain what happened to his science-loving, ambitious child, who had wanted to join the U.S. Air Force and then study law, he said.

“She had a 96 average in a special class. I don’t know what happened,” said George Molina.

“A classmate in one of her classes kept telling her she was a slut, she’s a whore. I don’t know why they kept telling that to my daughter,” the girl’s father said.

“She told me, ‘Daddy, I got bullied,’” he said.

A friend of Gabby’s said the pretty, dark-haired girl had a compulsive cutting habit — and kids teased her about it and about her recent split with a boyfriend.

Her parents refused to comment on the allegation that Gabby had a history of self-harm.

“(Gabby) said that she wanted to move schools because she felt uncomfortable. People wanted to jump her and people bothered her,” said schoolmate Samantha Martin, 12.

The bullying occurred online and at school, Samantha said. The guidance counselor had been trying to help, she added.

“They gave (Gabby) a notebook to write in,”said the 12-year-old.

“She used to cut herself. People knew she was cutting herself,” Samantha said.

Part of the angst stemmed from problems in the Molina household, the girl said.

“They had a lot of problems. They fought a lot,” she said.

Still, she said, Gabrielle outwardly kept a positive attitude most of the time.

“She was always happy. She was smart. She liked science,” Samantha said.

Other classmates said they were unaware of Gabrielle’s internal strife — although some students said her sister had posted a photo of her cut arms on Instagram. Photos on that account have since been removed.

“I never saw (the picture). She seemed so happy. I can’t believe she would do this. I’m very surprised,” said one seventh-grader who declined to give her name. “If something was happening, she should have spoke up.”

Police are interviewing Gabrielle’s friends and relatives to learn more about her suicide. Schools Chancellor Dennis Walcott said he’d spoken with Gabrielle’s family and offered his condolences.

“Any child that takes his life or her life is something that deeply concerns me and hurts me as a parent and not just as a chancellor,” Walcott told the Daily News.

“Bullying is something that I feel very strongly about. We are always looking at new ways to work on the issue.”

Walcott plans to visit IS 109 Friday, he said.

Education officials have refused to comment on allegations of bullying among IS 109 students, citing a police investigation.

But the junior high has a history of harassment back to at least 2010, according to the city’s annual school surveys of students and parents.

IS 109 earned a “C” for its school environment in the city’s 2012 progress reports, when 80% of students said there was bullying at the school and just 70% of kids reported that they felt safe in school hallways and bathrooms.

In 2011, 84% of kids reported that students threaten or bully other students at school, and in 2010, 78% reported bullying at the school.

IS 109 Principal Karleen Adam Comrie declined to comment.

Staffers have established a crisis team at the school to offer counseling for students and staff.