"Martin was there for her during a challenging time in her life and it was something she will always be grateful for," a Klum friend told People.
In addition, the supermodel and Kirsten reportedly decided to end their professional relationship.
"They are no longer working together," another source close to Klum told the magazine. "Life is about timing. He was incredibly supportive and they were there for each other, but they're moving on now. They still have a great friendship."
Klum and Seal, 50 -- whose divorce has yet to be finalized -- are the parents of four children Leni, 8, Henry, 6, Johan, 5, and Lou, 2.