IMO, I would suggest something like" W, remember when you agreed to full transparency, to put my mind at ease, I would like full access to your phone, email etc".
If she has anything to hide she will turn it around on you and say you are being controlling. If she has nothing to hide she will show you to put your mind at ease.
This is good, but I also know she is wise and will have already deleted anything that could be revealing. Ultimately this will make me look controlling and I'll feel like an idiot.
