Document everything. In the meantime, teach the nine year old how to take care of herself and her sibling. Watch her brush her hair, brush her teeth and teach her to do this for her sister. A nine year old should be able to do this unless she is just rebellious. You can teach her to bathe the two year old as well or at least sponge her off. Tell them why it is important to keep clean and change their clothes each day even if no one makes them. And send mosquito repellent with them or whatever you think they might need when they visit their dad until you can get the situation under control. Just do the best you can do. BTW, if she won't take care of brushing her hair tell her you will just cut it short. If she wants that then cut it and if she doesn't then she will make sure her hair is brushed. Maybe this is a good time to teach personal responsibility to the oldest since her dad isn't doing anything for them.