How can the believing sister who is cursed and verbally abused by her mother be overcome by the deterioration of her psychological state?

If a mother curses and supplicates against her daughter, she is in error, for the Prophet, peace and blessings be upon him, forbade a person from supplicating against themselves, their child, or their wealth. Nevertheless, it is not permissible for the daughter to abandon her mother or treat her poorly. Rather, she must honor her and treat her kindly, even if the mother is abusive. This is based on the Almighty's saying: ﴿Indeed, he who fears Allah and is patient, then indeed, Allah does not allow to be lost the reward of those who do good.﴾ She should also speak gently and deal with her mother kindly, returning evil with good, for the Almighty says: ﴿And not equal are the good deed and the bad. Repel [evil] with that which is better, and thereupon the one whom between you and him is enmity [will become] as though he was a devoted friend.﴾ If the daughter fulfills her duty of honoring her, then her mother's anger or supplication against her will not harm her.