As Southern Charm‘s Kathryn Dennis and Thomas Ravenel battle over custody in court, she is remaining focused on the two priorities in her life: her young daughter and son.

“Kathryn’s kids are her priority. If she really thought she was doing any harm to them whatsoever, she would want the best person to take care of them,” a source tells PEOPLE about Dennis, 26, who shares daughter Kensington Calhoun, 4, and son St. Julien Rembert, 3, with ex Ravenel.

Get push notifications with news, features and more.

“She’s involved in their lives. She has the energy to be silly with them; to play board games and do art projects. She’s very hands-on, nurturing, and playful with them. And she wants them to be happy; she wants them to be safe. She really does have their best interests,” the source shares. “Even with the divorce, she was the one who wanted them to see a therapist — to get help, and get counseling. She thought any child going through this situation, it could help.”

Image zoom Kathryn Dennis/Instagram

Since Dennis and Ravenel, 56, split, the two have been going head-to-head in court to iron out custody of the children.

She lost custody of the kids and entered rehab in 2016 after she failed a drug test, testing positive for marijuana.(Years earlier, Ravenel went to a 30-day rehab program himself; he served 10 months in federal prison after being indicted by a federal grand jury in June 2007 on a charge of conspiracy to possess with intent to distribute less than 500 grams of cocaine.)

In 2016, Ravenel was awarded full custody, but Dennis has since earned back 50/50 custody. And in October, she filed documents in Charleston seeking to obtain primary custody of the two children, and on Nov. 6, Ravenel filed a counterclaim, vehemently denying all of Dennis’ allegations.

In new court documents filed in the County of Charleston, South Carolina, and obtained by The Blast, Ravenel made numerous claims about Dennis, including that both of their children have “developmental and behavioral problems” as a result of her.

“The parties’ youngest child, S.J.R., has developmental and behavioral problems that have required intensive therapy. Father is informed and believes that these problems are the result of Mother’s drug and alcohol consumption while S.J.R. was in utero,” the documents state.

Image zoom Thomas Ravenel, son Kathryn Dennis/Instagram

The source tells PEOPLE, “Kathryn thought Thomas’ filing was vile. To suggest she was consciously drinking and doing drugs even after she knew she was pregnant is completely disgraceful and not true.”

In a statement, the former politician’s attorney Kelley Dupre Andrews-Edwards tells PEOPLE, “Mr. Ravenel’s counterclaim against Ms. Dennis is a verified pleading, meaning he swore under oath as to the truthfulness of the allegations made therein. No attorney would counsel their client to verify a pleading unless evidence existed at the time of filing to substantiate his or her claims. Mr. Ravenel’ s sole concern is and always has been the safety and wellbeing of the parties’ children.”

PEOPLE is out to Dennis’ attorney for comment.

“Kathryn doesn’t deny her past. But she hasn’t gone near any drugs in years. She’s done all these modifications in her life because she knows it’s best for her going forward. She doesn’t drink, even though she’s never had a problem with alcohol, just because she wants to be present. It’s frustrating for her that something where she messed up in her early 20s is now going to dog her for the rest of her life, especially in a situation like this when Thomas uses that,” the source says.

The source believes that Ravenel’s recent filing “is a deflection” of his own legal issues.

“He knows that there’s far worse things coming out about him — be it his criminal case or the civil case — and he’s trying to make a big fuss about Kathryn to pivot. He’s very Trumpian in this matter,” the source says about Ravenel, who was arrested and charged with assault and battery in the second degree in September following allegations of sexual assault brought against him by his children’s former nanny.

The source continues, “If you truly thought your children were in danger, why would have waited until she filed something? She was triggered to file the custody adjustment after he got arrested — what’s his trigger to file this, other than revenge?”

In his recent filing, Ravenel claims, “[Dennis] values fame, celebrity, and the life of TV stardom above the needs and wellbeing of the parties’ minor children.”

But the source says: “If she looks happy, he’ll do anything to make her suffer. It’s not what normal, healthy parents do. The children deserve better from their father, they really do.”

“Thomas has yet to make them a priority. This filing wasn’t to help them, it was to hurt her,” the source says.

In Ravenel’s filing, it states, “when Father is working, Father has an appropriate and experienced caretaker who sees to the needs of the minor children.”

According to the source, “Anytime he has the children, he has nannies around the clock to take care of them. Kathryn doesn’t have that, she has her kids alone.”