Thanks for explaining what you're looking for and what you've been trying to do. I see now where you're coming from. 
 ::::If you don't accept that brain death IS death, it will be difficult for you to accept that she was dead when she was released and there will be no way to prove it to you. For myself, it's easy to accept that her body was dead because the brain controls the body and while we can artificially animate or replace different organs, we can't animate or replace the brain. Since her brain is dead and without mechanical intervention her organs would cease to function, in my mind she's dead. It used to be that medicine only recognized death as being when the heart stopped but that was before the heart and lungs could be kept on artificial support.   
 ::::As for your claim that if there is one kind of thing there must be necessarily be others, well, that's logically false. Having one thing does not guarantee the existence of another thing.