Should a wife who does not pray, hates her husband's family, and tries to cause discord among them remain, or should she be divorced after the husband has come to detest living with her and the Istikhara prayer yielded no clear result?

The questioner is advised to strive diligently to reform his wife, especially concerning the matter of prayer. If her family is corrupting her, he has the right to prevent her from visiting them or from him visiting them. If this does not help, then it is better for him to divorce her, because one should not keep a wife who neglects her obligatory duties towards Allah. In this case, divorce might even reach the level of being obligatory. Regarding Istikhara, the preponderant opinion is that one should proceed with the matter after performing it, and not abandon it unless Allah diverts him from it. One should not wait for a dream or anything similar.