I think your plan of avoiding all dealings with her for the rest of the time she's there is excellent. Ugh I can't imagine having to deal with someone who is passively aggressively leaving scorched earth behind at the job....I'd still keep tabs as best I can do on what she's doing and try to work around her as much as possible.

FYI: I have a feeling she may be trying to get a job with one of the sponsors, so don't be surprised if she appears in your orbit again