According to The Mirror, the Primeval actress had been invited to the music mogul's 50th birthday party, but wanted to avoid the celebrations after learning that she would soon become front page news.
It is thought that Rouass phoned Cowell to apologise for her absence before being convinced to forget the row and attend the bash as planned.
A source said: "Laila was distraught at first, but Simon was brilliant. He was just what she needed.
"And when she got to the party last Saturday, he and Sinitta looked after her. Everyone was very kind to her."
Professional dancer Du Beke recently made a public apology after a Sunday tabloid revealed that he had called Rouass a "P**i" during rehearsals.
Rouass has already announced that she wants to move on from the controversy and continue dancing with Du Beke on Strictly.