I’ll go with sailor on this one. There is no reason to be confrontational if up until now she has paid her rent on time and been a good tenant. I don’t agree that you need the services of an attorney yet either, unless you are in a lease agreement. Assuming that you have no written agreement, since you didn’t mention one, the norm in most states is 30 days notice. Depending on circumstances like how difficult it is to find similar rentals in your area, and how egregious her conduct has become, you might even consider offering her 60 or 90 days to vacate.
I like lawyers, really I do but often the best solution is to keep things low key, rather than jumping to the legal system.
Vindictive tenants can make the transition a nightmare. Instead of looking up an attorney, you might consider looking up the services of a property management company. Property management is very effective in a case such as yours, since you can then be a neighbor to your neighbor, rather than a landlord to your tenant. It takes a lot of pressure off to be able to pick up the phone and call the management company with a problem.