People (besides niles,) shouldn't get angry at free, as mean as she is.
Her problems go beyond what can be induced by a short stint in an abusive hospital. That's why, die yuppie, she just can't drink it off, or have a conversation.
She has some sort of thought disorder, hence the disorganized, non sequential ramblings. She can't respond to your questions because she can't really absorb them, and keep them in mind long enough to form a response. The delusion that niles is threatening her is part of her psychosis. The constant disorganized writing is also a symptom. It's sometimes referred to as hypergraphia or scripting
I'm not saying this to be glib or presumptuous, but someone who knows her here should STEP IN and direct her towards services. I'm not saying hospitalize her, but having a "companion" to constantly talk with will help her organize her thoughts, perhaps ss can help with that. Also, being away from her parents who are (supposedly) abusive will help, too. Services can help her arrange an apartment, or a stay with a caring couple, or family member. I hope someone steps in, because she's a tragedy waiting to happen when she misidentifies someone as being abusive and "strangles them", or if she simply wastes away, deeper and deeper into psychosis.
And, please, no. I'm not a shrink, but I speak from experience