All in the Family: Donald Trump’s Niece on the President’s Clan

A name you should know: Mary Trump

Trump at the 1990 opening of the Trump Taj Mahal in New Jersey with, from left, his brother Robert and wife Blaine Trump, parents Mary and Fred, and sister Maryanne Trump Barry. (Charles Rex Arbogast/AP)

Who she is: She is Trump’s niece, the daughter of his older brother, Fred Jr., who died of alcoholism in the 1980s.

Why you need to know about her: Because she’s writing a tell-all about the president. It sounds like fodder for Trump’s critics who want to try to get into his head to diagnose his behavior. Mary Trump is a psychologist, and in a teaser on Amazon posted Monday night, she said she will describe “a nightmare of traumas, destructive relationships, and a tragic combination of neglect and abuse” that made Trump into who he is today.

What else is interesting about this: We haven’t heard from Trump’s extended family much before this, and certainly not in a salacious, tell-all way. They seem to have an implicit pact to stay quiet — until now, five months before the election. The family history we already know sounds like a soap opera. As The Washington Post’s Michael Kranish reports: There’s also a battle over Fred Jr.’s fortune, and an allegation Trump and his siblings pulled funding for Mary Trump’s nephew who has cerebral palsy.