my 2 cents, for whatever they are worth (probably about 2 cents, actually). Your daughter may be testing the limits of your love for her. It sounds like Dad has already kicked her out, which must really hurt. By keeping her in your home you are not enabling anything she does. You are telling her that you love her, even if she does things you don’t approve of. That love may the only thing that anchors her, today, & in the future.
As far as the other kids…it certainly is tricky. Can you explain to them that Sister is not behaving properly, but that we all should feel sorry for her because she is not happy & is struggling with her Yiddishkeit right now? This way the younger ones know Sister is wrong, and they know that even though you don’t approve of her lifestyle, your love is something they can always depend on. That sense of security is so important…in the long run I think the healthiest message ALL children can ever hear is that you (meaning parents) will always love them & be there for them despite their undesirable behaviors.
Is it possible to set down some house rules with your daughter? If you ask her for the sake of the other children to refrain from XYZ in the house, would she be responsive?
May Hashem give you strength and patience in large measures.