My 9 year old daughter

This doesn't sound productive. I'm sorry. It also doesn't sound beneficial for her in the long run.

The part that feels a bit off here is her enjoying pushing you over your threshold and that is a very dark part of our society. Somehow, you need to A. become her most valuable support and B. work out where she's being dominated in this way and learning that this is OK. 

It could be good to get an understanding of what's happening - does she feel ignored and forced to unreasonable expectations in other ways? Is there a family member who enjoys teasing her who she feels irritated by? 

We all want things. Usually autistic individuals end up in defence mode and want to be left alone or want help. But when anyone just wants a type of undisciplined 'freedom' which is harmful to another, they are eventually rejected by society. 

It may be wise to send the cat to a friends house or parent for a little bit of time if you need be. But it's far more important you become incredibly reliable. This may mean making responsible adjustments. Considering a yes or no and then sticking to it no matter what. 

I would also find movies you can watch together which can help her understand principles of being human. 

I can recall being young and rarely feeling this kind of enjoyment of another's suffering except in extreme cases of injustice or being so well beyond my threshold that some very dark human-ness emerged. For spite and even a kind of sadism, one has to be incredibly battered and abused, neglected and dismissed. But for a child who's life feels like chaos, it could simply be they desire a parent to assert order and boundaries and act like shield. She might need protection in loads of little ways - all matters of sensory elements and cruelties at school. Something is going on and maybe it's time to find a therapist?

Maybe your child is PDA, pathological demand avoidant?

I have 2 children who both have diagnosis of ASD but my eldest is the PDA’r he is always ADHD.

Your daughter sounds a lot like my eldest son. It’s incredibly difficult to raise a child with PDA. 

You feel helpless and pushed to your limit everyday. 

Do you reduce all demands put upon her? Do you have specialist support involved or social work? 

Sorry your going through such difficult times. X

Can we shoot each other ? - i have lived with an undiagnosed one of your daughter for over 30 years, but they get better.

Maybe your daughter is one of the guys where one way to deal with it is that never get the reaction they expect. In that context it may a common knowledge starting point, but it can move on to more. A specific form of focus that atypifies can be picked up on. A place to move forward for adaptation, even when driven absolutely nuts or until or nerves are sensitised and tingling. Jokes about suicide in a poignant way just to stay sane as the irony does help i found as well. We know its not a demon in them ( ofc ) its not a evil streak ( ofc ) & ofc its not permanent in such overt intensity. Though my other half is a life long emotionally needy person, but has evolved her drivers & is perfectly in balance mostly. Is your daughter is diagnosed ? - this area is certainly one of the mysteries entrenched within the asperger girl dilemma / how they differ from the boys / and what drivers or can be unrelated. Definitely the parent central nervous system in overdrive on the edge of despair is something experienced by many. And possibly its like becoming a actor going for an oscar in not reacting once nerves are in tatters. Then theres the rest of the cast & how hard it'll be to get a whole production together. But it might be the thing that delivers, as there is such a good chance that the behaviour will remodel itself into gaining the feeling of well being another way.  It could be true to say that feelings of well being is gained by the disruptive behaviour. IF it is then not only self explanatory but the key insight. Many asd girls do this & as such its a keen area of research looking to understand the drives more.

Anyway that could be something or nothing - good luck - i hope it calms down whatever you find that works & something will.

I’m so sorry - that sounds incredibly stressful and difficult. It’s so different to my experience with my own autistic children (I’m also autistic). 
what does she say about why she is behaving in this way? It seems so extreme. Is it an outlet for stress she is under at school maybe? Does she behave well at school - or are there problems with her behaviour at school too? 
is there anything that really calms her and settles her?