"With full hearts, @laurawbush and I are delighted to announce the birth of our new granddaughter," the 43rd president posted. "Barbara gave birth to Cora Georgia Coyne on September 27, 2021, in Maine – not far from our family home where Barbara and Craig were married. Cora is healthy and adorable, and we are proud and grateful."
Former First Lady Laura Bush also posted photos on her Instagram page.
Bush's 39-year-old daughter Barbara gave birth to her first child earlier this week alongside her husband, screenwriter Craig Louis Coyne.
The two married in 2018 in a private ceremony in Kennebunkport, Maine.
Cora is the former president's fourth grandchild. Barbara's twin sister, Jenna Bush Hager, has three children with her husband Henry.