The 14-year-old from Hesleden, County Durham, was among the favourites to win the $1m (£760,000) prize on Wednesday.
The "America's Got Talent" season 13 has arrived.
"I love everything about you, I love your look, I love your style, I love your voice". Every time you perform, people are going to remember you.
Another of the judges, Mel B, described Courtney as a "free bird" saying she was "wild and crazy". "I don't think I've ever smiled this much in my life".More news: North Korea summit: Kim pledges nuclear cuts if Americans follow suit
Earlier in the series, Howie had used his Golden Buzzer on Courtney to secure her place in the quarter finals.
Courtney was in the final pair alongside her fellow singer, Michael Ketterer.
Speaking to the MailOnline, Tom Storey said the United Kingdom "doesn't get her", adding that the family was "confident she will do well in the US".More news: Audi e-tron SUV officially sees the light of day
Tyra then told her: "You are incredible. You were fantastic. My prediction is you're going to be the victor". The spinoff, America's Got Talent: The Champions, will premiere January 1, 2019. Before Tuesday's performance, she thanked fans on social media, saying she had had "an awesome time".
"It's like Garth reached into my heart and pulled out the lyrics of this song", Ketterer said.
Which is why Ketterer's mind-blowing follow-up on Wednesday, where he penned an incredible new song called "The Courage to Love", wowed the judges and earned a standing ovation from the audience.More news: Arsenal boss Unai Emery confirms Bernd Leno will make debut against Vorskla