I have a co-worker who seems to act friendly face to face,

but I have observed her to be a gossipmonger and to talk badly about people behind their backs while seeming to be friendly on the surface.

She is also constantly complaining about her job, her boss and the organization in general.

Lately there has been some tension between us because of my annoyance with her.

My distrust of her is bubbling to the surface and I am getting more and more overt, finding less, and less patience in listening to her and her complaints and talking about people.

Now I feel she may be trying to get other people to talk about me behind my back, ruin my good reputation, and make me the butt of jokes among my co-workers.

How do you deal with a girl like this?

Ignoring her and trying to be civil is not working in terms of making me feel better