Maria Shriver "cannot make sense" of the death of her cousin Tatiana Schlossberg

She wrote on Instagram: "I return to this space today to pay tribute to my sweet, beloved Tatiana, who left this earth today. I return to this space to pay tribute and honor her loving and supportive family, who came together and did everything they possibly could do to help her. I return to this space heartbroken because Tatiana loved life. She loved her life, and she fought like hell to try to save it.

"I cannot make sense of this. I cannot make any sense of it at all. None. Zero."

Tatiana - an environmental journalist and the granddaughter of late US President John F. Kennedy - first revealed her terminal diagnosis in a first-person essay for The New Yorker in November, where she explained she was diagnosed with cancer shortly after the birth of her daughter Josephine in 2024.

Maria, 70, said: "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, courageous.

"A few weeks ago, Tatiana wrote so beautifully about her diagnosis and her battle with this horrendous disease. If you haven't read her words, please honor her by doing so. Her piece is extraordinary. Whatever your faith, please pray for Tatiana and her grieving family. Tatiana was the light, the humor, the joy. She was smart, wicked smart, as they say, and sassy. She was fun, funny loving, caring, a perfect daughter, sister, mother, cousin, niece, friend, all of it..."

And, Maria vowed to look out for Tatiana's family members including her husband George Moran, their children Eddie and Josie, Tatiana's parents Edwin Schlossberg and Caroline and her siblings Rose and Jack.

She wrote: "My heart has always been with my cousin Caroline ever since we were little kids. My entire being is with her now. What a rock she has been. What a source of love she has been with Ed, Rose, Rory, Jack, George, Eddie, Josie, and all of Tatiana's cousins and friends and the amazing doctors who tried so hard.

"Those of us left behind will make sure Eddie and Josie know what a beautiful, courageous spirit their mother was and will always be. She takes after her extraordinary mother, Caroline. May we all hold Tatiana's family in our collective embrace not just today, but in the days ahead, and may each of you who read this know how lucky you are to be alive right now. Please pause and honor your life. It truly is such a gift."