Shelton performed at military bases in Britain during World War II. Her radio programme, "Calling Malta", was broadcast from 1942 to 1947. In 1944, she was invited by Glenn Miller to sing in France with him and his orchestra. She declined because of prior commitments. Miller died during this tour when his plane crashed. Shelton appeared with Bing Crosby on the "Variety Bandbox" radio programme. In 1948 she recorded "If You Ever Fall in Love Again", written by Irish songwriter Dick Farrelly, who is best remembered for his song "Isle of Innisfree", which Shelton also recorded. Her songs "Galway Bay" and "Be Mine" were popular in the United States in 1949, and she toured there in 1951.