Facebook: How to block someone from seeing your updates but stay friends?

[jaw dropper]

My sister came back from college - who is disgusted by the thought of me. And my Mom was pleasant while my sister was gone. Now that my sister is back my Mom is reminded of how much the family despises me.. .............................................................. HOW DO I BLOCK THEM WITHOUT DELETING THEM ON FACEBOOK?

[Yahu]

When you update you status, there's a little box underneath that says 'public' (default setting) you can click that and change it to private, or you can choose particular people for whom it will be visible or not visible.