Is my friend being nosy by looking at my Facebook wall to walls?

a friend of mine is also a “friend” on facebook, but she doesn’t use it – doesn’t comment, doesn’t post things on her wall, etc. She even said that she joined it but never uses it. However, the other day she mentioned a comment someone made on my wall. Is she being nosy by reading my wall to walls? I know i can restrict her but i didn’t think i would have to.