Is the speaker considered mistaken in her behavior towards her husband's nephew, her husband, and her son, and is she considered to be unfair to them, especially with her concern for her daughters?

The questioner mentioned several matters concerning the young man living with them: 1. He is in a relationship with a girl and exchanges romantic and indecent messages with her. This is a reprehensible act that he should be advised against, and he should not be allowed to access the internet through their subscription for this purpose. If the questioner intentionally looked at his page without his permission, she has sinned, as it is a type of forbidden espionage unless absolutely necessary. 2. He took some items and did not return them. The questioner erred by accusing him of exploitation and theft initially, as the default is to assume good intentions for a Muslim. 3. He exploited her son and took a coupon from him. He may not have exploited him if the son was an adult and sound of mind and gave him the coupon willingly. However, if he was a minor child, his gift is not valid.

As for the questioner's request for her husband to expel the young man, she has no right to do so unless the house belongs to her, or if the young man is not in a separate part with his own facilities.

Forgiving those who do wrong and responding to ill-treatment with kindness is a great principle in Islam, and it is incorrect to claim that this principle is not suitable for this era.

It is advisable to ease the matter for oneself, not to burden it more than it can bear, and to strive for understanding with the husband to raise the children on the principles of religion and noble morals, and to protect them from corruption.