Beau Biden's Widow, Hallie, Is Dating His Married Brother Hunter: Read the Family Statements. Beau Bidenâs widow, Hallie Biden, is dating his married brother, Hunter Biden â and the family is totally OK with it. According to Page Six, Hallie and Hunter, 47, started dating after the death of Beau, who died in May 2015 at the age of 46 after suffering from brain cancer. Find out more in the video above and details below.