Jules Stewart filed the petition to separate from John Stewart on August 17 in Los Angeles, reports TMZ.
The documentation, which was apparently filed without the help of a lawyer, reveals that Jules and John have been estranged since June 15, 2010.
Jules is a writer and director, while John is a television producer and stage manager. They have been married for 27 years.
Kristen is also facing her own relationship troubles after she was caught cheating on Robert Pattinson with her Snow White and the Huntsman director Rupert Sanders.
On August 28, it was reported that Pattinson is selling the Los Angeles house he shared with Kristen and is now considering moving back to the UK.
Pattinson and Kristen will appear on screen together for the last Twilight movie - The Twilight Saga: Breaking Dawn - Part 2 - out on November 2.
Watch the trailer for The Twilight Saga: Breaking Dawn - Part 2 below: