Unfortunately, I feel like she presents better than me because I try NOT to bring up bull
PLEASE READ and just try to be polite. She tells lies and acts so (what appears to be genuine) and my silence and discomfort appears to be nasty.
It is likely that some people will believe her, at least at the beginning. There's not really a neat and tidy way to handle these scenarios. I've found the approach you're taking to be the most effective in the long run. In my experience, trying to get people on your side and convince them that you're right can backfire sometimes.
So you'll see her at the party? How do you feel about that?