George Bush paid tribute to his late mother, Barbara Bush, in the post, writing that his daughter and mother share similar traits. "I'm so proud to be this beauties sister".
Laura Bush called it "a wonderful day".
Barbara Bush and Craig Coyne at their wedding in Kennebunkport, Maine.
George W. Bush and his wife Laura live in Preston Hollow.
The family-only ceremony was held outside, overlooking the ocean at Walker's Point, where the elder Mr Bush - who is now 94 - lives.
"A former First Lady of the United States of America and relentless proponent of family literacy, Barbara Pierce Bush passed away Tuesday, April 17 2018 at the age of 92", read a statement from her husband, former President George H.W. Bush, who also attended the Sunday wedding.
And some details: "The bride wore an ivory silk crepe Vera Wang custom gown and was escorted by her father and grandfather".
The wedding ceremony was a true family affair, with the bride's aunt Dorothy Bush Koch officiating.
"A very short, sweet ceremony", Barbara told People magazine.
Sisters Jenna Bush Hager, left, and Barbara Pierce Bush talk about their famous parents and grandparents September 26 at the Abilene Convention Center in Abilene, Tex.
The pair met on a blind date in November, and got engaged in August, setting up what People calls "a whirlwind, five-week engagement" in which Coyne moved from California to NY.