I agree with Starsky. To what end? Has she said she wants to work on M in a credible way such that you believe her?
I think not. She just coasting. You don't need intel, you need a plan.
You say you want intel to see if she's still seeing OM or not. Why? What are you going to do if she is? Why aren't you doing that now? How long do you wait to become plan A?
Your best chance of becoming plan A is to behave as if you will never be plan A.
You are stuck, my friend.
Looks like Zew beat me to the punch. This is precisely where I was going with my questions.