After Jack Schlossberg’s sister, Tatiana, has spoken publicly about her devastating terminal cancer diagnosis, some of his past detractors are offering apologies.

A source tells Page Six that Jack — the TikTok influencer and congressional hopeful son of Caroline Kennedy and Edwin Schlossberg — faced Internet trolls earlier this year when he suddenly shaved his head, with online commenters chalking it up as a stunt for attention.

We hear haters came after Kennedy scion Jack Schlossberg after he shaved his head. jackuno/ Instagram

“He wrestled with telling social media why he shaved his head — because he was so castigated for it,” says a pal. “Some of the haters were using it to say ‘Look. Look. He is crazy.’ Despite all that, he refused to exactly say why he did it. It wasn’t his news to share. It was his sister’s.”

But Jack, who’s known for his sometimes zany social media posts, shaved his head to support his sister during her cancer battle.

“Now people know and they know a lot more about who he is as a person,” says the source. “Some people have reached out to basically say ‘I’m sorry I said s–t. I didn’t know.” 

Trolls are now apologizing after learning about his sister Tatiana’s terminal cancer diagnoses. AFP via Getty Images

Tatiana detailed her diagnoses in a moving essay in the New Yorker. Getty Images for New York Magazine

Tatiana detailed in a moving New Yorker piece how she was diagnosed with acute myeloid leukemia immediately after giving birth to her second baby with her husband, George Moran, in May 2024.

We’re told that watching his sister navigate the healthcare system — combined with his own difficult back surgery several years ago — had a major impact on the way the Kennedy scion views his political mission.

Earlier this month, Jack announced he was running for retiring Rep. Jerry Nadler’s seat in New York’s 12th Congressional District.

We’re told healthcare will be a large focus on Jack’s campaign. @jackuno/Instagram

Both Jack and Tatiana are critics of their cousin Robert F. Kennedy Jr. CBS via Getty Images

“He’s seen the healthcare system up close,” the insider says. “Jack is going to make healthcare a huge piece of his campaign, especially because he has a family member [Robert F Kennedy Jr.] directly undermining it. People will vote for Jack to send a message to RFK Jr., too.”

Jack has struggled with back pain similar to his legendary grandfather, JFK, and has had two hip procedures.

In Tatiana’s moving essay, she detailed her grueling treatments and calls out cousin RFK Jr., the current US Secretary of Health and Human Services, whom she calls an “embarrassment to me and the rest of my immediate family.”

Tatiana’s article thanks her family. Penske Media via Getty Images

“I watched from my hospital bed as Bobby, in the face of logic and common sense, was confirmed for the position, despite never having worked in medicine, public health or the government,” she wrote.

In the piece she criticizes the “Make America Healthy Again” leader’s positions on vaccines, reproductive healthcare and research funding.

Jack reacted to his sister’s story on Instagram the day it came out, posting a photo of a concrete road followed by a picture of a blue sky.

Jack posted this the day the article came out. Jack Schlossberg /Instagram

“Life is short — let it rip,” the 32-year-old wrote atop both images.

Tatiana credits her husband and family with keeping her company during her hospital stays and helping take care of her 3-year-old son and 18-month-old daughter.

“My parents and my brother and sister, too, have been raising my children and sitting in my various hospital rooms almost every day for the last year and a half,” she wrote. “They have held my hand unflinchingly while I have suffered, trying not to show their pain and sadness in order to protect me from it. This has been a great gift, even though I feel their pain every day.”