A legal expert explains what's next in Robin Thicke and Paula Patton's custody battle

Paula Patton and Robin Thicke have been attending family therapy together in the midst of their contentious custody battle, and sources have told PEOPLE both parents are committed to putting their 6-year-old son Julian‘s best interests first.

“The family attended their first joint therapy session this weekend,” said a source familiar with the situation. “Ms. Patton will continue to do what is right for her son.”

A second insider told PEOPLE, “Robin wants to keep Julian’s best interests at heart.”

If they can’t work out their issues privately, Patton and Thicke could be back in court soon, explains L.A. family law specialist Stephanie Blum, who’s not involved with the case.

Patton, 41, filed legal documents on Thursday asking to limit her ex-husband’s joint custody of Julian, accusing Thicke, 39, of physical abuse, including spanking Julian excessively. A school mediator and principal said in her court filing that they also became concerned about Julia and called L.A.’s Department of Children and Family Services, which is investigating. Thicke denied committing any abuse in a court filing, and on Thursday an L.A. judge denied Patton’s request.

“For the sake of their son, it would be better for the whole family if they could reach some agreements on how both parents will discipline Julian and settle their issues amicably outside of the court system,” says Blum.

Credit: Dimitrios Kambouris/Getty Images for GQ

But Patton could still go back to court to try to alter their custody agreement.

“Paula’s request was made on an emergency basis, and courts do not like to make orders modifying custody on an emergency basis unless it is clear that a child is in imminent danger,” explains Blum. “The judge didn’t believe that it was an emergency requiring immediate action. That doesn’t mean that Paula could not ultimately succeed in convincing the court to modify the custody orders. She will just have to file her request in the ordinary course and wait the six or eight or so weeks for the court to hear the matter after Robin has been provided proper notice and the time to prepare his response.”

In court, “the judge will give each side an opportunity to tell their story and it will be up to the judge to decide whether a change in the current orders is justified,” says Blum. “In the meantime, presumably DCFS will finish its investigation and come to some conclusion.”

Patton and Thicke could also reach an agreement outside of court. According to Thicke’s court filing, he and his ex-wife had agreed to undergo mediation before initiating any legal proceedings. Says Blum of the family therapy sessions: “It remains to be seen whether it’s a good sign or just them fulfilling a requirement they had previously agreed upon.”