Despite their decision to divorce after 13 years of marriage, Gwen Stefani and Gavin Rossdale are staying united for their kids.

"Their priority is making sure they maintain a safe and secure home for their children regardless of what's happening. When you're separated and have kids, you're much more emotionally invested," a source close to Gwen told People on Tuesday, Aug. 4.

gwen stefani and gavin rossdale kids

Gwen, Gavin and their sons Zuma (left) and Kingston (right) in June 2013.

Gwen, 45, and Gavin, 49, married in September 2002 and have three sons together, Kingston, 9, Zuma, 6, and Apollo, 17 months. "Knowing how she is as a mom, her top priority is making sure her kids feel secure and comforted during the process," the insider added.

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The couple announced their separation on Monday, Aug. 3 with the following joint statement to TMZ: "While the two of us have come to the mutual decision that we will no longer be partners in marriage, we remain partners in parenthood and are committed to jointly raising our three sons in a happy and healthy environment."