After McPhee, 39, shared on Friday that she and Foster, 73, experienced a "horrible tragedy" in their family, sources tell PEOPLE that 2-year-old son Rennie David's nanny died suddenly.

Isabel can't believe her eyes when Nanny McPhee, the extraordinary government nanny, shows up at her front door after the events of Nanny McPhee (2005). As Isabel's scheming brother-in-law ...