The source tells People that despite Kim "trying her best," the past month or so has been very hard on the reality star with her divorce looming.
"December was a rough month for Kim," the insider explains. "She has been living separately from Kanye. Over the holidays, it was hard for her to stay positive."
The source continues. "She has been trying her best, though, for the kids. She stayed in Los Angeles for New Year's [Eve]. Kourtney and Khloé [Kardashian] were around to support her. She is very grateful to have her sisters to lean on."
Though Kim is lucky to have family to depend on right now, she is still worried about the divorce, especially how it will affect her kids.
"She is sad about it, of course," the source explains. "She just feels she has done everything in her power to make her marriage work. Even though she has been thinking about divorce for months, she hasn't filed because she feels terrible for the kids."
Right now, the kids are staying with their mom at their family home in Hidden Hills, California.
The source tells People, "She provides a safe and stable environment for the kids. She is a great mom and the kids will be fine."
According to Aimee Gold, a high-profile family lawyer in Los Angeles, who spoke to Page Six about the upcoming divorce, the parents will most likely get "50/50" physical custody. However, if one side can prove a situation would be "detrimental to the kid," that number might be adjusted.
Beverly Hills lawyer Joseph Mannis of Hersh Mannis LLP, who also contributed to the article, adds, "If you file a divorce case in California, neither party can take the kids [out of state] without the other [parent’s] permission."
He explains, "Oftentimes, there’s an argument about this in celebrity cases."
Considering Kanye's newfound love for his Wyoming ranch, it definitely seems like a possibility that this situation will arise when it comes to settling custody.