She's got Brynn Hartman syndrome, insisting on the "Dr." monicker. (Not being as famous as her husband) BTW, Brynn shot and killed Phil and herself back in 1998, she was so jealous.
Even Uncle Joe explained back in 2009 why she went for a doctorate @ the age of 55 !. "She was tired of seeing mail addressed to Senator Biden, and Mrs. Biden" And that's right from the horses ass. She is a Doctor with the same degree as "Doctor" Bill Cosby...