My friend's step son accessed his biological mother's email account on the step-mom's computer. Can it...?

be used in court against the account owner (the ex-wife, mother of the kids). There were very graphic emails about an affair she had while married. There were many emails calling the judge and attorneys stupid because they "believed her lies". She was sending emails to her lover bragging about taking the ex-husband (father of the son, husband of the step-mom) and taking his banking information, applying for loans in his name, selling the kid's ADHD medications and more. My friend is wondering that even though the computer screen was open in front of her, and had been activated by the step-son that she could get in trouble with the court for bringing it up. She and the husband have made accusations against the ex-wife about her affair, and about her abusing his credit, but had no proof until these emails. She printed them all, and re-closed the screen afterwards.

She believes the child (age 10) was shocked at what he read, and is seeking help by leaving it open in front of her. There were things very graphic on there about the ex-wife's lesbian affair. Arkansas is the state.