"Heather knows why and when her marriage ended with Richie and she knows why my marriage ended with Charlie"

Denise Richards is likely describing completion of her marital relationship with Charlie Sheen and her friend Heather's marital relationship with Richie Sambora. Denise is suggesting that Heather and her both understand why their marriages ended, and that they can associate with each other because regard. This quote suggests that Denise and Heather have actually had discussions about their particular divorces, which they have a good understanding of the scenario. It could also be translated as a sign of uniformity in between the two ladies, as they both have gone through the exact same experience. Denise's quote suggests that she and Heather have a strong bond, and that they can rely on each other for support and understanding.