Ann Peacock has been brought on board to write the screenplay for Walden Media's "American Girl." Goldsmith-Thomas Prods. and Julia Roberts' Red Om Films are producing.

American Girl is a popular line of historically accurate dolls and books for girls. The company is a subsidiary of Mattel. While the doll line runs the gamut from pre-Revolutionary War to World War II, the film will focus on Kit Kittredge, who grows up in the early years of the Great Depression.

The movie is being produced by Elaine Goldsmith-Thomas, Marisa Yeres and Stephanie Langhoff through Goldsmith-Thomas Prods. in association with Roberts and Red Om's Lisa Gillan.

Peacock was a writer on Walden's "The Chronicles of Narnia: The Lion, the Witch and the Wardrobe." She is repped by CAA.