Is it permissible for the sister to request a divorce due to her disapproval of the groom and her claim of deception, and is she obliged to return the Mahr (dowry), the wedding jewelry, the cost of the engagement dinner, and everything the groom paid if she insists on the divorce?

The Shari'ah has permitted the prospective spouses to see each other, as this fosters lasting affection between them. However, if the marriage contract is concluded without them having seen each other, it is valid, and neither party has the option to annul it if the other party turns out to be different from the description given. The advice for the sister is to be slow in seeking divorce and to consider her husband's situation. If she dislikes continuing with him, it is permissible for her to seek a divorce, and he may compel her to accept khul' (divorce at the wife's instance, usually by returning the mahr) in exchange for relinquishing the mahr, unless he deliberately deceived her. If the divorce occurs, the wife is entitled to half of the mahr. The husband may reclaim gifts unless he committed deception, or if the gifts were given for maintaining kinship ties or as charity. If khul' occurs, it will be according to the agreement between them.