Bush's line got a laugh from his audience at the U.S. Hispanic Chamber of Commerce.
Jenna and her fiance, Henry Hager, have decided to be wed at her parents' ranch in Crawford, Texas, rather than at the White House. The White House has refused to release any details, such as the setting on the ranch, who has been invited and how many people will attend.
Bush's wife, Laura, has described the soon-to-be married couple as "soul mates" and has said the president likes Hager.
"He's a really good guy," the first lady said recently on "The Early Show" on CBS.
"He's finally going to be the son that George never had," Mrs. Bush said. Jenna has a twin sister, Barbara.
Bush joked later at a National Republican Congressional Committee dinner that Laura Bush could not attend because she was busy planning the wedding.
At the Kuwaiti ambassador's residence, where the president stopped by for an event on malaria, Bush made fun of his future son-in-law's marriage proposal.
"So the guy comes to see me and he says, `I want to marry your daughter,"' Bush said.
Bush said he replied, "Done deal."
Bush said he was late getting to the event because his wife had him watching "Father of the Bride."
"I didn't finish it," Bush said. "I'm going to make my remarks short and go home and watch it," he said.
