Patricia, who is Gisele's fraternal twin, married Rodrigo Pereira at the Laurentia Vineyard outside Porto Alegre. Gisele, 29, served as maid of honor – leaving Brady, 32, in charge of the diaper bag.
The evening coincided with Earth Hour, when people around the world turn off their lights for an hour as a symbolic commitment to the environment – a gesture the wedding guests also observed.
According to a post on Gisele's official blog, "When it was time to turn the lights off, Patricia made a brief speech about the importance of everyone doing their part for the environment. The lights were turned off and the place was lit only by candles. At the end, all the guests gave a standing ovation."
This is baby Benjamin's first trip abroad, and the first chance for most of Gisele's family to meet him.
With reporting by CHARLOTTE TRIGGS