It's not easy to figure out what it is that's triggering the person, as they generally `go away' when triggered, so they aren't aware of it. A semi-impartial observer can notice that whenever a certain thing happens, she goes away. Once the trigger is identified, you do your best to avoid it. Perhaps the therapist can get to the root of it later on.

Switching also takes place when one of the alters takes control. This will all have to be worked on within her system and with the therapist. Give up any notion of control here. Just try to work with whatever you're handed. You'll develop skills you never knew you had.