I'm in the middle of a mess with an office gossip right now!
Mom always told me that a gossip is a gossip, and if they talk about others they'll talk about you. It seems like a compulsion with some people. I like to believe that it's got something to do with serious inferiority issues.
My office gossip gets on my nerves often, but, like you, I usually try to just go along and not say anything. I do have to work with her and her office is across the hall from mine. I run into her all day long. unfortunately for me, I'm her latest target.
Our boss hauled me into her office a couple of weeks ago asking me all sorts of questions like, "Are you happy here?" and "What are you working on?". Those questions led into her saying, "Well, I've been told that you are on the phone about your house a lot, to the point where you are neglecting your obligation to help others in the office."
That was it. I immediately knew who the culprit was and how this all evolved. I was furious, but like an idiot I cry when I am angry. That's another mess in itself.
It took about an hour right then and about a week afterward to show my boss that not only was this all a crock of poo, but the person responsible was dropping her own ball, all by herself.
Point being, watch your back, Jenna. If someone spreads hurtful, damaging gossip about one, they'll do it to you without thinking twice whether or not it's true.
Sorry to ramble. She almost cost me my job and it's still a very fresh wound.
But you asked how to get her to stop...ignore her. She won't stop. It's probably her nature. But if you ignore her, at least you won't be in the middle of whatever she stirs up. Guilt by association is never a pretty thing.