@Ann287 No, there's no way to get her banned or warn others, except to post a warning about her on a local Facebook hosting group.
Took a quick look at your profile and see that you are an experienced host. I guess you've not run into this sort of thing before, though.
If it were me, I would disengage with a guest like this, not waste my time with her. Someone who bombards you with endless questions and keeps trying to communicate off platform is a huge red flag. I would have told her that you don't think your place will be a good fit for her, and stopped communicating, blocked her number on my phone and clicked on the report flag and said she was harrrassing you.
I guess she instant booked after all that? You didn't accept her request, did you?
Sometimes hosts will block a day in the middle of the dates an objectionable guest requested for a few days so they can't book.
You can still report her to Airbnb. Tell them she kept insisting on communicating off-platform, they hate that. They won't likely ban her, but they'll probably make a note of the report on her account.