" She did admit to me that she would call him from time to time to tell him she's safe and ok."
What did you say to this? NO CONTACT MEANS NO CONTACT. EVER.
It needs to be 100%, and she needs to be transparent with you. I'd strongly suggest YOU lead here Peter, and show her what this looks like.
Affairs are HIGHLY ADDICTIVE. You don't ask the alcoholic or the gambling addict how they are going to prove to you they are no longer drinking or gambling. You hold their hand, give them tough love, and you LEAD.
