What is the ruling on a wife disclosing her husband’s work secrets to her boss (who is her sister's husband), which resulted in problems at work and in the marital relationship?

The questioner made a mistake by divulging his work secrets to someone not authorized to see them. Similarly, his wife made a mistake by divulging them to the work manager. Divulging is a betrayal of trust, and she must repent and be warned against repeating it. The questioner must forgive her, while directing her that her action was impermissible, and he must, in the future, safeguard his work secrets. She may have committed another error if she was in seclusion with a man who is not a mahram to her.