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.
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.
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 I especially like the whooshing sound they make as they go flying by") was originally made by Douglas Adams, author of The Hitchhiker's Guide to the Galaxy (2005).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. On the DVD commentary track, Nora Ephron says that the book that the publishers actually gave to the real Child and Beck was "Helen Corbitt's Cookbook," a 1957 bestseller by the Director of Food Services for the Neiman-Marcus Department Stores.
In the movie, Simone Beck and Julia Child have a contentious lunch with Louisette Bertholle in which Beck insists that because Bertholle has done so much less work on the book than they have, she should be credited as "With Louisette Bertholle" in smaller type under their names. Because Louisette reveals that she is going through a divorce, Julia takes pity on her and says that they should all be credited equally, in alphabetical order - which is how they really were credited on the first edition of Mastering the Art of French Cooking, Volume 1. However, after Julia Child became a famous TV personality in America, later editions of the book featured her name alone and in large type above the title, with both Beck and Bertholle in much smaller type below the title.