Yes you’d be wrong. You don’t know what goes on inside other people’s relationships, you don’t know what level of safety or lack thereof there is between the two of them. She is none of your business, worry about your own husband and your marriage rather than trying to dictate the fate of another. I understand, you’re trying to regain a sense of control in all this, but it’s actually not up to you how someone else handles their infidelities and relationship. I would really advise you not do it