im sorry you have to get through this, mental illness is real illness but so is drug addiction. focus on the silver lining if you can, she isnt in jail for murder so thats something “you still have” its so hard to be optimistic especially with tough situations and this illness but as humans to avoid suffering we have to invent value in whats left over after something is taken away, like her freedom for instance. even terminal illness patients try and do this to preserve a good enough mood.
give her books that focus on people who have to live in jail forever, or even worse get the executioners chair. i hate the phrase “think positive” because no one is positive all the time. what people should really say is something like “distract yourself with negative that could have happened” this stuff at least for me makes really hard times bareable. just the really difficult times.
distract yourself from the bad feelings into a mood of appreciation. if someone substantial is taken away from you, all we can do is count over and over again what we have left. easier said than done, but i hope this helps. she might not have freedom but at least now its a stable place to stay. easier said than done, but its what ae have to do in order to fight depression.