It's difficult to know exactly where the MR stands, if you have nothing but her saying she ended the A. I think you need to have a transparency plan.
I told you about the shape I was in when I ended my A. I can relate to how she's acting. However, without you having some means to back up what she claims, she could just as well still be involved with OM. And while I'm thinking about it, let me throw this in, too. After I ended my A, then it was several weeks of him floating around in my head, so it was like keeping the A alive. When I recognized what was happening, then I had to really work hard at kicking him out of my thoughts. It took months for me to work through the ordeal.
Since I was receiving guidance from the DB board, I knew I needed to give my H assurance that I had ended the A, so I made myself transparent. He didn't have the DB tools, so I had to take the initiative. It was for both our sakes that I needed to be transparent. I needed to be accountable. Sure, I had bought the prepaid phone, had access to other computer, etc., but I realized that if I was going to get over the affects of the A, I had to be a open book. If I had not had support from the board, and my H, I seriously doubt I would have made it through.
If your W is not receiving the guidance and support, and is not transparent...........she could have a rebound A, or return to OM, IDK. I think you should approach her with your concerns and talk about a transparency plan. She gives you all passwords and/or account information. She should have one phone, and you can look at it without notice. If she balks on any of these, then there a very good chance the A is has not ended and all this was to throw you off. Btw, her volunteering to show her phone is useless. Of course, if she is not serious about working on the M, she'll find a way to bypass all these obsticals.
If she starts with the old, "You just want to control me", tell her "It's not about control. I am trying to protect our M and give myself assurance you are sticking to your word". If she says here phone/emails are private..........then, enough said right there. You will have your answer. Do not accept any "you will just have to trust me" b/c she can't be trusted at this time. Tell her, "I want nothing more than to be able to trust you again. Considering your recent betrayal, it isn't that simple anymore".