What is the religious ruling regarding this woman who mistreats her daughter-in-law verbally, physically, and through slander? Is it permissible to supplicate against her and dislike her? Is what is happening considered divine wrath or a sign of shortcoming? And with what should the wife supplicate to rid herself of this harm?

It is permissible to supplicate against the oppressive mother-in-law to the extent of her wrongdoing, though forgiveness and forbearance are preferable. There is no sin in disliking her due to her actions, while being careful not to let this dislike escalate. Affliction is not necessarily a sign of Allah's wrath; rather, it can be a sign of His love. One should renew repentance and avoid sins that may be a cause for affliction. Supplication is beneficial for repelling evil, and among the narrated supplications is: "O Allah, we place You against their throats, and we seek refuge in You from their evils."