How can the husband's female colleague be kept away from their lives, especially after the husband has taken possession of the wife's money, and his actions have aroused suspicion and a lack of trust?

The wife’s salary and possessions are her private property, and it is not permissible for the husband to take anything from them except with her consent. The wife is not obligated, according to Sharia (definition), to bear any expenses; rather, the financial responsibility falls solely on the husband. Nevertheless, helping the husband in these matters strengthens intimacy and love between the spouses. As for the husband's relationship with his female colleague, it is one of the gravest sins because it involves disobeying Allah and corrupting a woman against her husband. Being alone with a non-mahram (definition) woman is forbidden, even if lust is not intended, and a man must lower his gaze, especially a married man who should keep himself chaste with his wife. Therefore, it is imperative to ensure the husband repents, and to advise him, remind him, encourage him, and warn him with verses and hadiths. Furthermore, cooperate with him to attend scholarly gatherings, encourage him to associate with righteous people, cooperate in righteousness and piety, and utilize impactful events to advise him.