Sonja is a character who was Uncle Gary's fourth wife. She appears in the fifth book, Diary of a Wimpy Kid: The Ugly Truth. She and Gary were not supposed to get married as Gary was going break up with her to date her sister but when they were on a date at a baseball game, a plane flew overhead carrying a banner reading "Marry me Sonja?". She says 'yes', thinking it was for her, but it was for another Sonja. She and Gary most likely divorced after finding out he wanted to break up with her at their wedding party, since she does not appear in The Third Wheel.
- Linda, is the name of the woman whom Gary married in the online version. (Note: His first wife from the books is also Linda)