Is it permissible for children not to visit their mother if she expels them every time they come?

If the mother is harmed by her children's visits and expels them, then there is no blame upon them for not visiting her. However, they are obligated to treat her kindly, spend on her if her maintenance is incumbent upon them, and attend to her affairs. But if her expulsion is temporary for a specific reason, then they should choose appropriate times for visiting her, shorten the duration of the visit, bring gifts, and fulfill her needs.