Amaro, 19, beat out fellow finalists Josh Krajcik and Chris Rene to win the $5 million recording contract on Thursday night's finale.
"Oh, my God! Oh, my God! Oh, my God!" People.com said Amaro exclaimed as she dropped to her knees to pray.
"Thank you so much!" she said. "I don't know what to say. Thank you. God is good."
"America, thank you for giving this girl an opportunity," judge and producer Simon Cowell said on her behalf. "She is a star."
People.com said auditions for Season 2 of "The X Factor" are to begin next month. The show is based on the British series by the same name, on which Cowell also served as judge for several seasons.