Is the prayer of a mother against her children for evil and curses answered when there is no reason or justification for it? And what is your advice to us and to her in this situation?

We advise you to fear Allah and to be patient with your mother, offering her advice gently and compassionately, and obeying her except in matters of disobedience [to Allah]. For Allah does not waste the reward of those who do good deeds. What the mother engages in, such as insulting and cursing, is a grave sin. The Prophet, peace and blessings be upon him, said: "Insulting a Muslim is wickedness," and "It is enough evil for a person to despise his Muslim brother." It is obligatory upon her to repent, apologize, and obey her husband, for her obedience to her husband is one of the greatest deeds that bring one closer to Allah. The Prophet, peace and blessings be upon him, said: "Any woman who dies while her husband is pleased with her will enter Paradise."