One of the sources says the wedding will be held at the president's ranch in Crawford, Texas.
"It's going to be a small wedding," the source tells PEOPLE, adding that Jenna has already selected her bridesmaids. "She's very excited. They make a great couple."
The couple's engagement was announced in August. First Lady Laura Bush told PEOPLE in November that she "of course" fancied the idea of a White House wedding herself. It "would be a lot of fun," said Mrs. Bush. "But I also know it wouldn't be very private. And of course we want to do what Jenna wants to do."
At the Bushes' gated, 1,600-acre Prairie Chapel ranch, the ceremony and reception could be held far from the prying eyes of the White House press corps and paparazzi.
Hager, 29, a former Commerce Department staff member who's in his final year of the MBA program at Virginia's Darden School, first consulted Jenna's twin sister, Barbara, about his intentions to propose to the 26-year-old.
"That was really sweet, because they have such a close relationship, Barbara and Jenna do," Mrs. Bush told PEOPLE. Then, on the overlook outside the president's cabin at Camp David, Hager asked the president and first lady for their daughter's hand. They kept the plan secret from their daughter for more than a month until Hager proposed to Jenna on Aug. 15.
"I am thrilled for Henry and Jenna, knowing how great marriage can be," said the president.