Tatiana Schlossberg's cousin Maria Shriver is mourning her untimely death at the age of 35. "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," Shriver, 70, wrote via Instagram on Tuesday, December 30. "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.