She had a No.1 hit song in 1956 in the UK with "Lay Down Your Arms", engineered by Joe Meek. She also had a Top 10 hit in 1961 with her cover version of "Sailor". In the same year she participated in BBC Television's contest, the UK qualifying heat for the Eurovision Song Contest. Her entry, "I Will Light a Candle" was placed fourth. Shelton made another attempt at Eurovision in 1963 with "My Continental Love" – and came fourth again. In addition to her hits "Lay Down Your Arms" and "Sailor", she also charted with other hits in the late 1950s with "Seven Days" and "The Village of St. Bernadette". In 1967 she covered the song, "It Won't Be Long 'Til Christmas" which was originally to be featured in the Walt Disney feature film musical, "The Happiest Millionaire" but then was deleted from the final cut of the film. Shelton's versions of the song have since been featured on several compilation recordings.