President Trump's choice to represent the United States at the Vatican, Callista Gingrich, has one especially prominent achievement as a Catholic: She is responsible for her husband, former House speaker Newt Gingrich, converting to Roman Catholicism in 2009."When Newt became a Catholic, it was one of the happiest moments of my life," she said in a 2012 interview with The New Yorker.Callista Gingrich was raised in Wisconsin as a Catholic, but attended Luther College in Decorah, Iowa, affiliated with the Evangelical Lutheran Church of America, on a music scholarship. She has been an accomplished pianist since childhood and also plays the French horn. For the past 20 years, she has sung professionally in the choir of the Basilica of the National Shrine in Washington, D.C.Her husband began attending mass at the Basilica largely to watch her perform in the choir, and he told the Catholic TV network EWTN in 2011 that it was that worship experience that led him to convert to Catholicism."I was doing that as a supportive husband, and it sort of caught up with me in a way I could never imagine," Gingrich said.Trump's choice of Callista Gingrich to serve as U.S. Ambassador to the Holy See will require Senate confirmation. There is little sign of opposition to her nomination, but it is not without controversy. She carried on an affair with Newt Gingrich for several years while he was still married to another woman, and their relationship troubled many conservative Christians.Before marrying her, the twice-divorced Gingrich had his previous marriage annulled. Under Catholic church teaching, divorced Catholics are not supposed to receive communion unless they have their former marriages officially annulled.Whether that history would taint her ambassadorial service at the Vatican is by no means clear. Newt Gingrich is one of President Trump's strongest supporters, and Callista Gingrich may well be seen by Vatican authorities as carrying her husband's political clout.The White House statement announcing her nomination highlighted her role as president and CEO of Gingrich Productions, a multimedia production and consulting company, and her authorship of the bestselling Ellis the Elephant children's books. In 2010, her production company released a film called Nine Days That Changed the World about Pope John Paul II's 1979 pilgrimage to Poland and the role it played in the downfall of communism in eastern Europe. Copyright 2017 NPR. To see more, visit http://www.npr.org/.