Because of Meryl Streep's height (5'6") several camera/set/costume tricks had to be employed to mimic Julia Child's height (6'2"). Countertops were lowered, Streep wore extra high heels, and forced perspective camera angles were used.
Eric Powell's quote ("I love deadlines. I especially like the whooshing sound they make as they go flying by") was originally made by Douglas Adams, author of The Hitchhiker's Guide to the Galaxy (2005). Eric explains this himself, immediately after delivering the line.
The Publishers at Houghton Mifflin show Julia Child a cookbook entitled 'Real Home Cooking' by an author named Della Simmons. Both the book and author are strictly fictional as there was no such book by an author with that name.
Louisette Bertholle is depicted here as a lazy shirker who doesn't carry her weight on the cookbook project. After the film was released, people who knew her came forward to declare that she was dedicated to the project and tested a huge number of recipes in her home. Eventually, she did have to scale back her participation in the project, but for personal reasons, as she was dealing with a bankruptcy (resulting from a failed investment) and a painful and ugly divorce. She eventually remarried happily and became a successful cookbook author on her own.
Julia Child and Simone Beck would collaborate on a second volume of "Mastering" in 1970; by that time Louisette Bertholle had remarried and was working on her own cookbooks. There was some discussion of a third volume of "Mastering" but Child and Beck would part ways professionally; Beck insisted on sticking to traditional techniques and equipment, and Child was enthusiastically embracing new techniques and finding ways of applying modern equipment to traditional recipes. While Child became an American TV personality, Beck continued to teach in France and published some of her own cookbooks. They were never to collaborate again but did remain friends for the rest of their lives.