"She feels like she spaced each child out just enough where it isn't too overwhelming for her," the source added.
In January, news broke that Kim and Kanye were expecting a baby boy via surrogacy. Kim confirmed the news later that month.
The 'Keeping Up With The Kardashians' star later announced her baby boy's arrival on May 10, tweeting, "He's here and he's perfect!"
"He's also Chicago's twin lol. I'm sure he will change a lot but now he looks just like her," Kim said of Psalm on Twitter.
Less than a week later, the 38-year-old star gave Twitter followers insight into her newborn's personality.
"We celebrated our baby boy about a week ago and now he's here! He's so perfect. I was freaking out for nothing because he is the most calm and chill of all of my babies so far and everyone loves him so much," she tweeted on May 11.
Psalm's arrival made Mother's Day even more special this year and especially "beautiful," as Kanye texted to Kim at that time.
"We are blessed beyond measure. We have everything we need," he added.
Last week, Kim's friend La La Anthony told US Weekly that the family is in good shape.
"Baby's doing good. Mom's doing good. Everybody's happy and healthy, which is always a beautiful thing," the actor said.
Kim and Kanye tied the knot in a beautiful ceremony in Florence, Italy, back in 2014 in front of friends, family and a star-studded guest list, reported E! News.
Kim and Kanye are already proud parents to son Saint (3) and daughters North (5) and Chicago (16 months).
Psalm is the power couple's second boy and the second time they have used a surrogate. They earlier used a surrogate for Chicago.