What is the ruling of the Sharia concerning boycotting a mother who favored her disobedient daughter and caused psychological harm to her righteous daughter?

Boycotting one's mother is impermissible; it is an act of disobedience (Uqooq) and among the gravest of major sins, for the mother's right is immense. Even if the mother has wronged someone, her right does not diminish, nor does it permit boycotting her. Ibn Abbas said: "Whoever angers their parents, Allah will not be pleased with them until they are pleased with them, even if they have wronged them." One must repent to Allah, reconnect with their mother, show her righteousness (birr), and treat her with kindness. As for the sister, wise people should be consulted to determine the best course of action with her.