Bewildered

[pearlharbr]

I called her mainly to let her know what our daugther had seen

So what was the other reason?

I explained there can only be positives if we give it another try

Reasoning doesn't work.

and that it would also help me out by knowing that we had both given it a shot.

Pressure. Fix things now.

I also said that if we agreed to something like that... we would both have to be faithful during that time.

More pressure. Trying to control her actions. Asking for a commitment.

I'm glad you feel in control of yourself. I'm glad that handling the convo in a calm manner is a good 180 for you. But don't start congratulating yourself on more of the same behavior (initiating R talk again, questioning her fidelity again, trying to convince her to come back again). It sounds like you're trying to fix her and that simply won't do you any good.