@David J. You may not be able to evict her yet, but you can definitely tell her you will give the poorest reference possible to anyone she tries to rent from in the future. I can't imagine anyone will want to rent to her. You should also mention that she is being disrespectful not only to you but to your other tenants who legitimately have issues paying and who want to pay and are actively working with you. That might be enough to get her to realize how stupid she is being. This is a Varsity Blues cheating scandel-esque slap in the face to good tenants who play by the rules.
For everyone talking about risk, this situation we are all in is so rare it's not really something you can screen for. You can rent to someone who exhibits all signs of being upstanding, but the fact is you never really know someone's true character until it itself is stress tested. But now that we know what some people are capable of, we can and should plan.