Angelina Jolie and Brad Pitt divorce: What's at stake

What is really at stake for Angelina Jolie and Brad Pitt's divorce?

The two may have made millions between them since marrying in 2014, but as the two negotiate the terms of their just-announced divorce, one expert says their biggest battle could end up being over children, not wealth.

Jolie filed for divorce Monday after separating from her husband September 15, according to court documents.

In her filing, the Jolie asked the court to grant her sole physical custody of the couple's six children, with visitation rights for Pitt, who would retain joint legal custody.

"Children are a very precious commodity that money can't buy," celebrity divorce attorney Neal Hersh told CNN in an interview. "So of course if someone is saying they want to limit your time with the children and you disagree with that, that becomes an area of contention and a significant one often times."

The couple's children are Maddox, 15; Pax, 12; Zahara, 11; Shiloh, 10; and twins Knox and Vivienne, 8.

It is not yet confirmed by either Jolie or Pitt's representatives if a prenuptial agreement was in place, but according to a Forbes estimate, the two have earned about $117.5 million since their 2014 marriage.

Hersh, who has over 40 years of experience in family law, said if a prenup exists, it would be a "thorough" document that would orchestrate the division of property in the case of divorce, including respective and joint earnings. In California, however, such agreements are prohibited from addressing issues of child custody.

"The issue here between these two folks -- if there's going to be an issue -- is going to have to be with the custody of their kids," he said.

In her filing, Jolie does not ask for spousal or child support.

Jolie is represented in this case by Laura Wasser, who was also her attorney during her split Billy Bob Thornton, according to a Bloomberg profile. Her other clients have included Gwen Stefani, Jennifer Garner, and Britney Spears.

In many high-profile celebrity divorces, the terms of the split are negotiated prior to filing official documents in order to preserve discretion. This was the case when Wasser arranged the 2014 divorce of client Melanie Griffith and then-husband Antonio Banderas, according to Bloomberg.

But Hersh said Jolie's "limiting" custody request indicates that was not the case here.

"That would tend to indicate to me that there's going to be contentious aspects of this and that it was not completely pre-packaged, if at all," he said.

"I am very saddened by this, but what matters most now is the wellbeing of our kids," Pitt said in a statement to CNN on Tuesday. "I kindly ask the press to give them the space they deserve during this challenging time."

A representative of Jolie indicated she shares Pitt's desire to keep their children out of the media spotlight.

"This decision was made for the health of the family," Robert Offer, an attorney for Jolie told CNN in a statement Tuesday. "She will not be commenting at this time, and asks that the family be given their privacy during this difficult time."