"The world thought I was writing this note to Bill Clinton. I am glad that I am not," Bush said in a letter welcoming Melania Trump to the "First Ladies' very exclusive club" after the 2016 election.
Asked in 2017 if she was still a Republican, the former first lady replied: "I'd probably say no."
"We thought, you know, he's just dying of a broken heart," said David Valdez, Bush's former official photographer.
George W. Bush spoke to his father by phone as the end neared.
Melania Trump's joyful reaction to Barack Obama was celebrated on social media.
"Barbara Bush filled our lives with laughter and joy, and in the case of her family, she was our teacher, our role model on how to live of life with purpose and meaning."
Widely beloved former First Lady Barbara Bush died Tuesday at the age of 92.
A Tuesday Twitter rant from Fresno State English professor Randa Jarrar said Barbara Bush "raised a war criminal" on the same day the 92-year-old died in Houston.
As America's First Volunteer, Barbara Bush has had to cut back on what she loves best: the hands-on volunteer work that has given her so much satisfaction over the years.
Barbara Bush was praised for her remarks about literacy but made controversial comments about Katrina and did not hide her dislike of Donald Trump.
The former first lady was only the second person to be both the wife and mother of a U.S. president. She died on April 17 at age 92.
Barbara Bush and Melinda Gates described the impact of the Ebola outbreak on women's health.