What is the ruling on divorcing a thin wife whose physique causes her husband to be repulsed by her, leading to marital problems and a lack of desire? And is the husband's continued presence with her considered an injustice to her, especially since it sometimes results in her humiliation due to his repression?

Divorce is permissible when there is a need for it, but disliked when there is no need. If you divorce your wife for the reasons you mentioned, you will not be oppressing her. However, divorce is not advisable due to the presence of your daughter between you, and your wife's thinness should not be a reason for divorce. Rather, it is better to restrain yourself with her to avoid temptations. Intercourse is a right of the wife according to her desire and your ability.

Marital problems should be avoided through patience and self-control during anger, and by ensuring that sound foundations are established for dealing with your daughter.

You may seek to marry a second wife while keeping the first one, if you are able to be just between them. However, if cohabitation becomes impossible and there is no way but divorce, and its benefit outweighs other considerations, then there is no harm in it. Allah may facilitate much good for both spouses after separation.