What is the ruling on a wife insulting (her husband) back in response to an insult, and is a husband entitled to abandon and insult her to please his sister?

The Sharia permits retaliation against someone who insults or slanders, but with conditions: retort with a similar insult without aggression, as Allah Almighty says: ﴿Whoever commits aggression against you, aggress against him in like manner as he aggressed against you. And fear Allah﴾. And the Messenger of Allah, peace and blessings be upon him, said: "What two disputing parties say is upon the initiator, until the wronged one transgresses." Also, the retort must not involve something forbidden, such as false accusation (qadhf) or declaring someone an infidel (takfir), nor should it involve insulting an innocent relative of the aggressor. If the retort adheres to these guidelines, then your husband is not permitted to prevent you, insult you, or abandon you. Rather, he must restrain his sister from misbehaving. However, if your retort involves aggression, then your husband is permitted to prevent you and abandon you as a punishment, and he is permitted to insult you with terms that describe your actions, such as "O oppressive one" or "O aggressor." However, insults solely for the purpose of wounding or revenge are not permissible. In conclusion, patience is advised.