Zellweger is seen smiling while holding an iPad, reported Ace Showbiz.
Sharon Maguire, who helmed the first film "Bridget Jones's Diary" in 2001, will also be back at the helm.
Zellweger is joined by another returning cast member, Colin Firth, who played her love interest Mark Darcy in the previous films.
Hugh Grant, who played Jones' other suitor Daniel Cleaver in the first two films, was originally set to reprise his role but he eventually left the project. "Grey's Anatomy" alum Patrick Dempsey was then brought in to join the movie.
It's reportedly based on columns written by Bridget Jones creator Helen Fielding and not adapted from her latest novel, "Mad About The Boy", in which Firth's character died.
