Did Ernest Hemingway Have Grandchildren?

Ernest Hemingway's oldest son Jack had three children (Joan, Margaux and Mariel), his middle son Patrick had one (Mina Hemingway) and his youngest son Gregory had eight (Lorian, John Patrick, Maria, Brendan, Patrick, Sean, Edward and Vanessa). Of Ernest's three sons, Patrick is the only one still living, but at the age of 85 is unlikely to father any more children. Margaux is the only one of the grandchildren who is presently deceased.