Is the wife sinful if she prevents her husband's sister from entering her home due to her many problems and her insolence towards the wife's mother, especially after learning of the sister's frequent visits to sorcerers and the husband's knowledge of this without him preventing her?

The basic principle concerning a Muslim is their innocence, so it is not permissible to accuse the wife's sister of sorcery except with clear proof.

If the house belongs to the wife, she has the right to prevent her husband's sister from entering it. However, if it belongs to the husband, she does not have that right unless she is certain of harm.

Visiting sorcerers and charlatans is forbidden. Those who do so must be advised and warned.

If the husband's sister is insolent towards the wife's mother, she is in the wrong and must repent and apologize to the wife's mother.