She was born to her stalwart father Jack Hemingway and her staunch mother Byra Louise in Mill Valley, California, in the United States. Jack was an eminent Canadian-American writer, conservationist, and fly fisherman. He was born on October 10, 1923, in Toronto, Ontario, Canada.
Jack passed away at age 77 on December 1, 2000. Furthermore, he was the son of Ernest Hemingway, a Nobel Prize laureate as well as a novelist. Besides, Mariel has twain appealing sisters named Joan Muffet and Margot Margaux. Joan became a model. On the other hand, Margot became an actress. Unfortunately, Margaux passed away at age of 42 due to a barbiturate overdose.