"Kim and Kanye are trying their best to keep their relationship issues a private matter, especially for the sake of the kids," the source says. "Kim is extremely stressed out right now between taking care of their children, studying to become a lawyer and figuring out her situation with Kanye in the best way possible for both their kids and for him and his mental state."
"She is doing her best to hold it together," ET's source adds, "but it has been overwhelming."
According to that source, the pair is on solid and amicable terms, though Kim is ready for any decision she needs to make -- especially when it comes to the well-being of their children. She and Kanye have four kids together -- 7-year-old North, 5-year-old Saint, 3-year-old Chicago and 1-year-old Psalm.
"Kim definitely has all of her ducks in a row with regards to the kids and financials in case she decides to officially file [for divorce]," the source says. "Kim still loves and supports Kanye and wants the best for him and their entire family. They are obviously still evaluating what that looks like exactly, but Kim is prepared across the board for anything that might come her way. Kim is worried and concerned that Kanye is not mentally stable enough to be the dad that their family needs."