What should I do about my sister who has removed her hijab and does not care for advice, and should I cut ties with her, or prevent my children from visiting her, or ask her not to come to my house, especially since my children ask about her and I do not know how to answer them, and they see her disobeying what I urge them to do regarding obedience to Allah?

It is recommended to be patient with the sister and supplicate for her guidance, and to advise her gently and wisely, reminding her that the hijab is an obligation. Someone who holds a respected position with her can be asked to advise her. It is permissible to shun her if there is hope that it will be beneficial; otherwise, it is better to avoid shunning and to conciliate her heart. If there is a fear of the children being corrupted by her visit, it is permissible to prevent them from seeing her while maintaining ties with her in other ways. Her entry into the house should be prevented if the benefit necessitates it.