You'll know soon enough. How she acts when she DOESN'T get her way on something -- or even if you're non-committal toward something (like "We'll see") . . . her true intentions will show.
I would just be wary. How is her VOICE? I believe that wayward spouses have this different voice they use -- one that perhaps you've never heard before. It's lilty, sing-songey even. Phony. Have you noticed that, and have you noticed how it's different when she's sincere with you?
Just a theory of mine, but it was certainly true in my wife's case. In fact, when I would listen to some audio recordings, it would literally make the hair on the back of my neck stand up. This was a woman who I'd been with for over 25 years, and I had NEVER heard the voice she was using. It wasn't her happy voice, nor her sad voice, nor her angry voice nor even her sexy voice. Not her "professional" voice that she puts on with her customers. Nothing I'd ever heard before . . . just different.