The high school accused her of making "false, misleading and harmful statements."
Olivia Jade Giannulli's high school has denied threatening and intimidating her former classmate.
Harlow Brooks claimed she was threatened by Marymount High School after posting her tell-all video about Lori Loughlin's daughter on Monday.
But in an exclusive statement to TooFab the elite LA private institution branded her a liar — who was only a pupil for three days.
"Marymount High School is proud to have a diverse student body, which is made up of students who come from a variety of ethnic and socio-economic backgrounds. Throughout its history, Marymount has empowered young women to live lives that make a difference, promoting change and good for the world," it said.
"It is unfortunate and disturbing that someone who spent only three days at Marymount would make false, misleading and harmful statements about the school and current and former members of its student body."
On Monday the vlogger shared a video detailing her experience at Marymount all-girls Catholic High School, in which she expressed surprise Olivia Jade had managed to somehow juggle the extensive workload, create YouTube videos and get accepted into the prestigious USC — especially since she wasn't a big fan of schooling.
The video quickly went viral — and things allegedly took a sinister turn not long afterward.
On Monday night Harlow posted a follow-up video, accusing pupils at the school — and even the school's newspaper — of making threats against her.
She said at least five of Olivia Jades' "sisters" threatened to sue her via direct messages, including one which read: 'I'm going to give you a few days to take this video down or I'm going to sue you for all of your money.'
Laughing it off, Harlow pointed out that in the original video she admits all she has "is my Subaru"; her lack of materialism being one of the reasons she only lasted one ill-fitting week at the elite school.
But shortly afterwards she claimed the Instagram page belonging to the school newspaper tagged a picture of her.
"The photo was a screenshot of my video, and when you swipe once it was a photo of like a ton of girls from the school all staring at the camera," she said. "And the caption on the photo was something along the lines of 'This going to be all of us showing up at Harlow's doorstep tomorrow."
Again, Harlow laughed it off: "Really? Y'all are going to show up on my doorstep? What are you going to do? Show up and write me some more strongly worded paragraphs?" she giggled, pointing out that to their credit, the threats boasted "incredible grammar."
"Wow I've never been threatened by a school newspaper before," she added.
And she claimed the threats weren't just virtual: while filming in her garage shortly afterward, Harlow claimed a "really, really nice BMW" with five teenage girls "all wearing massive sunglasses" pulled into her driveway and stared her down, before driving away.
"The interesting thing that's like completely ironic about their response to my video was the fact that they attacked me in the exact way that proved the concept of privilege that I was talking about," she concluded. "They literally threatened to shut me up and take my money because they didn't like what I was saying."
While Harlow has yet to mention it by name, she has shared screenshots of her wearing the uniform of the school, which counts Kim Kardashian and her sisters among its alumni.
Last week Olivia's parents were named in a fraud investigation involving dozens of wealthy parents, alleging the two celebrities paid $500,000 in bribes to get their daughters into USC as recruits to the crew team, even though neither of them ever rowed.
Harlow said in her original video she had "a hard time believing" Olivia Jade was not aware of her parents' alleged scheme.