In the opening credits of the hit OWN Network show “Welcome to Sweetie Pie’s” restaurateur Miss Robbie calls her son and business partner Tim her “rock and sometimes my hard place.” But it looks like the soul food cuisine duo might have found a mutual hard place — in front of a judge and jury.

According to court documents, Robbie Montgomery, the owner of the St. Louis-based Sweetie Pie’s chain, is suing her son, Tim Norman, for infringement of her trademark over the use of the “Sweetie Pie’s” name at restaurants he has opened in St. Louis and Los Angeles.

Montgomery, a former backup singer for the Ike & Tina Turner Revue, opened her first restaurant in Dellwood, Missouri in 1996 and registered the trademark in 2012, the documents say. Another location on Manchester Avenue in St. Louis is the best known, according to the St. Louis Post-Dispatch.

The show premiered on the OWN Network in 2011 and uses an unscripted format to follow the daily business and lives of Montgomery, Norman and their immediate and extended family as well as their employees as the business expands. It has become one of the network’s most successful shows. It has won two NAACP Image Awards.

With the help of the OWN show, the restaurant chain has become so successful that it even released a companion cookbook. In 2015, Montgomery began to grant franchises to authorized restaurants to use the trademark.

But Mongomery says in her lawsuit that Norman infringed on the trademark with the opening of an eatery known as TJ’s Sweetie Pie’s NOHO, which was depicted in a 2015 episode of the show and used signage with that name to promote it in marketing and in social media. Other restaurants in Berkeley, Missouri and Flourissant, Missouri were subsequently opened, each of which Montgomery says violates trademark rules.

“The fact Defendant Norman is identified as a member of Miss Robbie’s family on the Sweetie Pie’s Show, along with his position on the Show, further increases the potential of causing confusion in the market place,” the lawsuit reads.

Montgomery alleges that since the “Sweetie Pie’s” name is being used on the Los Angeles location negative reviews about the restaurant on the website Yelp will damage her brand. One review reads: “Huge fan of the show … love Ms. Robbie and the entire family…. The LA location is in dire need of Ms. Robbie to get the food on track.” While another reads: “I do not recommend spending your time or money on this place. Maybe we all need to go Ms. Robbie’s in St. Louis.”

She also says Norman has taken money from the Manchester location and used it for his restaurants. Despite demanding the monies be returned, Norman has refused, says the lawsuit, which seeks unspecified damages. Montgomery is seeking an injunction to have Norman cease the use of the trademark.

Neither Montgomery or Norman have commented publicly on the case.

“Welcome to Sweetie Pie’s” most recent episode first aired in January on the OWN Network.

However, tragedy has also struck the family recently when Montgomery’s grandson, Andre, 21, was shot and killed at a home in St. Louis in March. He had been featured in earlier seasons of the show.