Is it permissible for a wife involved in a dispute to reside in her married sister's house instead of her father's house, taking into account the living conditions of each?

If a wife leaves her husband's home without a legitimate Shar'i excuse and without his permission, she is sinful and disobedient (nashiz), and her right to financial support (nafaqah) is forfeited. However, the nafaqah of a pregnant nashiz wife is a matter of scholarly disagreement. If her departure is due to a legitimate Shar'i excuse, she bears no sin and is not considered nashiz, and she is permitted to reside wherever she wishes. Her residence in her married sister's home is permissible with Shar'i controls, such as her having a separate room, entrance, exit, and private facilities. As for her father's home, these controls are not required if there are no non-mahram individuals with her.