Watch: Jack Schlossberg Supports Sister Tatiana Schlossberg After Terminal Cancer DiagnosisMaria Shriver is commending Tatiana Schlossberg for her bravery. The I've Been Thinking... author shared some kind words for her cousin Caroline Kennedy's daughter after the 35-year-old wrote a moving piece for The New Yorker in which she revealed that she'd been diagnosed with acute myeloid leukemia, a rare blood cancer, with doctors giving her a terminal prognosis.