"... She is constantly lying, stealing, manipulating people to her will, and harming the animals or putting them in danger. "
These are some of the manifest symptoms of a sociopath, especially the manipulation and harming animals.
I agree with the other posters however it may also be good to look within the home at the dynamics going on, she is upset about something it is obvious does she have any siblings how does she get on with your partner does she visit with her Dad .,some of the behavior you describe is attention seeking .It is good to have her evaluated,but also check out .what the interactions are at home ..
Specialmom is correct - you need to see medical mental health specialist as a child psychiatrist or child neurologist. Your family doctor should be able to give you a referral to a doctor who has experience in this area. You mentioned two very, very serious mental health issues - and if true - either will require medication and therapy for a lifetime. Your first step should be to find a specialist to help you. This is not going to be an easy path - I wish you luck ...
Well, I think the first thing to remember is that you are being told she has a psychiatric disorder. Schizophrenia is a major illness and requires medication and psychiatric care. A therapist is excellent but she needs to see a psychiatrist and I would start there. So she is not trying to cause chaos in your life but is battling her own medical issues. This is important to remember when you are feeling so frustrated.
So I think your first step is to see a psychiatrist and begin treatment for her psychiatric disorders. That is more important than anything else. I'd also talk to your employer just so they understand that your daughter is suffering from a medical issue and that you are going to address it and hopefully things will get better. You appreciate what they've done, etc.
Does this girl have a bio father in the picture? If she does, perhaps he can help with the time and expense involved. If she doesn't, well that could be part of the emotional issues due to a situation that was created for her by the adults in her life.
As far as your significant other. Well, let me just say this. I would not be with a man that could not whether the bad times with me. That would make him an undesirable partner in my opinion. You are a package deal and whether it is a good one or not, this is your lot in life. You have a child that requires more than your average kid and that is just the way it is. Wish it weren't so and believe me I understand. I have a child with challenges as well. But what can I do? It is what I've been given to deal with. I'd want a partner that was supportive about it and not one that made me feel like it was even more of a burden. That is just how I feel about it.
Do you have any family that could give you a little respite help?
Again, I think your first order of business is to address her psychiatric disorders in a medical way. This will help all other things. good luck