You can manage who sees what, who can post what, who can comment on what.
For example: My parents are on facebook and I did not want my stuff to appear in their Newsfeed (because I get calls from them when DH or I post anything in the status...it's annoying. If I want them to know things, I will tell them) But I inadvertantly made it so that when they went to my profile page, they could just see what you'd see if I had not friended you. And yes, mom called me on it.
You could always friend the annoyance and then manage her access.