And so many showings.. that must be a great feeling.
You're doing some serious snooping, driving hours to the therapist's home, tech toys and apps. At some point the 'need to know' turns into a bitter elixir that's increasingly toxic. Remember in Lord of the Rings, Gollum was once a really good guy until the One Ring came into him possession, possessing him.
She's gone. No amount of fact finding, intrusions into privacy will change that. It hurts you far worse in the long run. In fact those actions could turn your step children away from you.
How long do you need to slam your head on a brick wall to figure out it's not good for you?
As much as you hurt, drop the crap, let it go. Be the man who shines forth on this board.
You're worth it.
*hugs*
Or you can do it Puppy style. Have all the information in hand, slam her with it and make demands. Then again, it depends on what you actually know to make that work.