Is it permissible for a woman to seek divorce in order to marry another man who is better in character and religiosity, and who is aware of her situation and wishes to marry her?

It is not permissible for a man to incite a woman to divorce [her husband] so that he may marry her, as this is a forbidden form of incitement (takhbib). However, it is permissible for a man to offer a khul' (divorce at the wife's instance, usually with compensation to the husband) to the woman's husband to free her from her husband's injustice, provided that his intention is to benefit her. The woman must be admonished against speaking with a non-mahram man. If her husband mistreats her, she has the right to divorce or khul' from him, and after her waiting period ('iddah) ends, there is no harm for any man to marry her.