I never believed that story. Ever. CW is a monster. And it looks like SW was very much in love, trying to make their marriage work.
It makes me see red when people say, "It takes two to break up a marriage.". Nope. One very selfish, uncaring person destroys a relationship. CW was out cheating on SW. The show illustrates how frustrated SW was getting with CW. But she was still trying to make it work.
I don't think SW realized the danger she or her children were in. But, she must have told her friend, Nichole, something that made her so insistent on the "Well Check", the very day she didn't hear from SW. Has that ever been brought up?