The former First Lady welcomed Mrs Trump into the First Ladies club. She wrote: “The world thought I was writing this note to Bill Clinton. I am glad that I am not.
“I wanted to welcome you to the First Ladies very exclusive club.”
She was reportedly “glad” Bill Clinton wasn’t about to fill her former shoes, USA Today reported despite believing Hillary Clinton would win the election.
At the time, Mrs Trump faced speculation as to whether she would stay in New York with son, Barron until he had finished the school year.
Some reports suggested she would not move to Washington at all.
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In response to this, Mrs Bush added: “My children were older and therefore I did not have the problems you do.
“Whatever you decide to do is your business and yours alone.
“Living in the White House is a joy and their only job is to make you happy.
“If you decide to stay in NYC that will be fine also.
“When you come to the White House let your son bring a friend.
“That is my unasked for advice.”
The letter will appear in the book, The Matriarch: Barbara Bush and the Making of an American Dynasty which goes on sale April 2.
The book comes out almost a year after Mrs Bush died on April 17, 2018.