The endgame here is to get her to move out. A reasonable person who refuses to pay rent or utilities and is not wanted would have no problem with this. The problem is I am not dealing with a reasonable person. Only someone who wants to inflict as much damage (emotional and financial) as possible.
I guess what I am asking is if you put yourself in this situation, what is the quickest and easiest, but legal, way to get her to leave. Or, get out of the lease without having to pay 6 months rent (as costly as it would be, I would even be willing to move all my stuff, rent a new place, and pay double rent until the landlord can find new tenants to move in; my only concern is if I do this, she'll refuse to leave or let new tenants move in and still pay no rent).
Keep in mind, she is already in debt and has little to no assets. So while it would be great to just front 6 months of rent and utilities for her; and let her cause havoc on my life for 6 months... there's little to no chance that she'll keep saved $900 let alone ($900 x 6 + utilities + any damages) at the end of 6 months. And even if she did, she'd refuse to pay it or spend it just so I wouldn't get it.
In this case, hindsight is 20/20, but I am trying to do whatever I can to resolve it the best now.