Which DCOM is based on a series of books by Deborah Gregory?

The DCOM based on Deborah Gregory's book series is The Cheetah Girls.

The 2003 Disney Channel Original Movie adapts Gregory's young-adult novel series about ambitious girls who form a singing group and pursue musical success. The film follows Galleria, Chanel, Aqua, and Dorinda as they navigate friendship, school, performance opportunities, and pressure from the entertainment industry.

Directed by Oz Scott, The Cheetah Girls stars Raven-Symoné, Adrienne Bailon, Kiely Williams, and Sabrina Bryan. Whitney Houston was among the film's producers. The movie became a major Disney Channel success and launched a film trilogy, with The Cheetah Girls 2 arriving in 2006 and The Cheetah Girls: One World in 2008.

The adaptation differs from the books in several ways. Gregory's novels center on five girls and use the fictional setting of the Jiggy Jungle, while the movie focuses on a four-member group in New York. Those changes still leave the title and central concept directly rooted in Gregory's work.