I got into an agreement with a real estate agent to show my country property. In hind sight I shouldn't have agreed to a 3 month contract! Now my financial circumstances are such that I don't need to sell (fully retired). But I have found out/overheard her telling a lot of crap to prospective buyers, even though I have told her the "right " answers. I know she can't have every property memorized and could make mistakes of course but she is telling outright lies. If someone gets into a contract believing those, and I didn't know, am I somehow on the hook?

You can be 'on the hook' in that a contract may fall through. What state are you in? First, contact the "broker of record". This is like the realtors boss. If you are unhappy with her, ask the broker to reassign another agent. I too would be nervous.

Well I'm talking about California, and I did get the agent's boss's name and number (from her.) I'm a little worried that if I report her to her boss, she will do even less than she has already to sell it?
She is lying to people about the zoning and what can be built there, she has printed up brochures with total lies in them and has them for display out front by the gate. I just took all the brochures out and threw them away without telling her. She also has not advertised my property other than a sign in the yard. When I asked her about it she said they don't advertise "that kind of property." Well how will anyone know it's for sale if she doesn't? I'm really really dissatisfied but like I said will probably just run out the clock and then get a different company.

First if you listed it, it is listed with the broker, not the agent, the agent works for the broker and the broker is also liable for lies told by the agent. So the broker needs to know and perhaps even report the agent to the state license board.

A home listed can be shown by other agents from other companies assuming you used a multi listing agency.

Better to not show it than have it shown under fraud issues