In early October, psychologist Stan Katz submitted a document to the Supieror Court of California, signalling an official custody evaluation has begun with potential interviews taking place with family caregivers and the six kids - Maddox, 17, Pax, 14, Zahara, 13, Shiloh, 12, and Knox and Vivienne, 10.
"The Pitt-Jolie kids are currently in LA for the evaluation process," a source told In Touch.
"What they say could ultimately decide everything."
According to In Touch, the kids will be taking sides when they finally open up about their relationships with their parents, the insider adds.
"The way it stands now, the kids just want it to be over.
"Most of them would be fine splitting half their time between Ange and Brad - but Angelina still wants sole custody."
The National Enquirer adds that the couple's two-year legal battle has caused all six kids to play favourites.
"Maddox wants to live with his father!" a source dished to the publication, adding, "Pax will go wherever Maddox goes - they're close."
The insider further dishes, "They want to hang with their dad. They think he's real cool."
"The younger ones, Viv and Knox, want to live with Ange and are that age where they still need their mum," added the source.
"Zahara is staying put with Ange, too - but Shiloh wants to live with her father. She's always sneaking in calls to him on what's going on."
The source finishes, "Angie sees it all slipping away from her, and is now so desperate she may resort to any dirty trick she can think of."
Both Jolie and Pitt are yet to comment on In Touch and The National Enquirer's report.