The 36-year-old married 37-year-old screenwriter Craig Coyne.
"I'm crying 24 hours later. I'm so proud to be this beauties sister", Jenna Bush Hager said along with a sweet photo.
"It was a very secret wedding, a little bit like my elusive sister, but also, just family in a place that means family love, and it was just handsome", she said. "But also, just family in a place that means family love, and it was just attractive".
Bush's daughter Barbara Pierce Bush was married to Craig Louis Coyne over the weekend in a secret ceremony.
The bride's twin sister, Jenna, wrote in an emotional post on Instagram, "Happy tears, heart exploding as I watched this lovely girl get married in the place that means love and family". "The private wedding was confirmed on social media by her parents and twin sister". Barbara Bush died at the age of 92 in April, leaving behind her husband, five children, 17 grandchildren and seven great-grandchildren. "But I ended actually with a letter that my grandfather wrote my grandmother, because I searched all the romantics and Shakespeare and it just wasn't doing it".
"My heart exploded last night as I watched my dearest sissy get married in Maine". "Laura and I are so proud of our compassionate, daring, fierce, kind, intelligent, loving daughter".
Her twin sister, Jenna Bush Hager, told NBC's "Today" show on Monday that Barbara wore something borrowed - a bracelet her grandfather had given to his wife on their 70th wedding anniversary. Coyne proposed at the same spot where George H.W. got engaged to Barbara.