Jack Schlossberg is breaking his silence on the untimely death of his sister, Tatiana Schlossberg. Jack, 32, took to Instagram on Monday, January 5, to share a tribute for his late sister. The post included several inspirational quotes, including one from Tatiana herself. "It's up to us to create a country that takes seriously its obligations to the planet, to each other and to the people who will be born into a world that looks different than ours has for the last 10,000 years or so," Tatiana wrote in her 2019 book, Inconspicuous Consumption. The quote continued, "Essentially, what I'm describing is hard work with possibly limited success for the rest of your life. But we have to do it, and at least we will have the satisfaction of knowing we made things better." Tatiana Schlossberg's Brother Jack Breaks Silence On Sister's Terminal Cancer Jack also included quotes from his and Tatiana's grandfather, former president John F. Kennedy, as well as Herman Melville, Alfred Lord Tennyson, Buddha, Abraham Lincoln, Robert Frost and more. The final image in Jack's post was a throwback photo of the siblings. News broke at the end of December 2025 that Tatiana died following a battle with cancer. She was 35 years old. "Our beautiful Tatiana passed away this morning. She will always be in our hearts," the JFK Library Foundation shared on December 30, 2025, in a statement via Instagram signed by Tatiana's husband George Moran, children Edwin, 3, and Josephine, 19, parents Caroline Kennedy and Edwin Schlossberg, siblings, Jack and Rose Schlossberg and sister-in-law Rory Schlossberg. One month before her tragic death, Tatiana revealed in an essay for The New Yorker that she was diagnosed with acute myeloid leukemia and given only one year to live. "I did not - could not - believe that they were talking about me. I had swum a mile in the pool the day before, nine months pregnant. I wasn't sick. I didn't feel sick. I was actually one of the healthiest people I knew," she wrote in November 2025. "I had a son whom I loved more than anything and a newborn I needed to take care of." Following the news of Tatiana's passing, several members of the Kennedy family paid tribute to the late environmental journalist. Kennedy Family Members Mourn Tatiana Schlossberg's Death at 35 After Cancer "I cannot make sense of this. I cannot make any sense of it at all. None. Zero," Tatiana's cousin Maria Shriver wrote via Instagram. "Tatiana was a great journalist, and she used her words to educate others about the earth and how to save it. She created a beautiful life with her extraordinary husband George, and children Eddie and Josie. She fought like a warrior. She was valiant, strong [and] courageous." Earlier on Monday, the Kennedy family gathered in New York City for Tatiana's funeral. The private service was held at The Church of St. Ignatius of Loyola on the Upper East Side. Moran, Edwin, Josephine and more were in attendance. That same day, the Kennedy family shared a never-before-seen photo of Tatiana posing with her loved ones prior to her death. "As we remember Tatiana and celebrate her life, our hearts are with her family and all who loved her," read the caption of an Instagram post shared by the JFK Library Foundation.