The musician, who appeared in the seventh season of American Idol, stars in the fourth offering in the P&G/Walmart 'Family Movie Night' initiative this Saturday.
The storyline revolves around a singer-songwriter called Sally (White) who is thrust into parenting alongside her husband Jason (Joe Flanigan) after her best friend passes away and she is named the legal guardian of her four children.
"I play a singer-songwriter which is such a stretch for me, you know?" she joked on a recent conference call to promote the project. "I was able to co-write three songs which I actually sing in the movie and Randy [Jackson] produced them."
She revealed that the opportunity had "come out of left field" and she had initially been unsure whether acting was even something that she wanted to pursue.
"My first day on set I was hyperventilating a little bit thinking, 'I don't know if I'm cut out for this!'" she recalled. "Then we got to filming and a week in I had been bitten by the acting bug and completely fell in love with the experience. It was better than anything I could have planned for myself."
She continued to describe the experience as "more fun than hard", but admitted: "I have been known to forget lyrics here and there - whatever! - so I was worried I would forget a line or two but memorising dialogue isn't as big a deal when you get there."
The movie also features a cameo from Jackson, who produced the soundtrack. "I was kind of playing myself," he explained. "I had a good time!" He also praised White's growth as an artist since her Idol days and predicted continued success.
"What excites me the most is always the artists - I'm not much on the popstar thing," he added. "The difference is that artists have long careers and popstars have the flash-in-the-pan careers - they're hot this year, lukewarm the next year and forgotten three yeas later. Brooke is really that artist and that’s what I love. She’s talented."
When asked if any other Idols could launch an acting career, he said: "I think a bit of being a great performer is a bit of acting. Adam Lambert certainly could do that - he's had a bit of a stage career before. I could see Chris Daughtry doing stuff; Kellie Pickler; Carrie Underwood... I think there are a lot of these kids that could."
"It's all about connecting at the end of the day," added White. "Whether you are on stage or screen, it's about making an authentic connection. That's what we have to do."
As for White's future in acting, she said that she was open to another performance but had nothing lined up yet, preferring to focus on the release of Change Of Plans.
"I think it's such a sweet, endearing film," she concluded. "It's all about these little moments between the characters that really define the story. The whole theme of it is that change of plans are better than anything you could have come up with yourself."
Change Of Plans premieres Saturday, January 8 at 8/7c on Fox. American Idol returns for a two-night premiere on January 19 at 8/7c on Fox.