The owner of Sweetie Pie's restaurants in the St. Louis area is suing her son, alleging trademark infringement because he is using the restaurant name at three of his own restaurants.

The St. Louis Post-Dispatch reports that Robbie Montgomery filed suit in federal court Monday against her son, Tim Norman, who operates two Sweetie Pie's restaurants in the St. Louis area and one in North Hollywood, California.

Montgomery's best-known Sweetie Pie's location is currently closed, but she operates another in Dellwood and The Upper Crust in midtown St. Louis. Her family and restaurant have been the subject of a TV reality show, "Welcome to Sweetie Pie's," on the Oprah Winfrey Network. The show's sixth season ended in January.

The suit seeks unspecified damages.

Tim Norman (at right) -- Getty Images for OWN