How should we deal with my brother's widow after discovering illicit romantic correspondence with another man, and what is our duty towards her, her children, and the man involved in this relationship?

After confirming that the woman has committed a forbidden act, she must be covered and warned about the consequences of her actions. If she repeats it, she should be threatened with exposure to someone who can deter her. If she does not desist, then it is necessary to inform someone who can deter her, while ensuring to prevent her from committing further forbidden acts. The children remain in her custody as long as she is trustworthy with them. The man who is messaging her should be rebuked, and the unlawfulness of his action should be explained to him. If he desires marriage, he should approach houses through their proper doors. If he desires an illicit relationship, he should be threatened with exposure to someone who can deter him, without causing him physical or financial harm. It is advisable to offer her marriage as a safeguard against the forbidden. It is cautioned against searching a woman's phone without her permission, unless it is necessary to prevent a forbidden act.