The troubled teen reportedly had suffered from depression and leaped to his death from the eighth floor of his apartment building in Los Angeles last Friday.
Marie's publicist Alan Nierob told E! News the family -- including Marie's ex-husband and Michael's father, Brian Blosil -- is expected to gather for the private funeral Monday.
A second source told E! News a viewing has been set for Sunday.
The Osmonds are originally from Utah.