This is something I would expect my wife to say. I'm assuming she's changed from the way she was then? I'm with Bigger in focusing on the fact that this is how she is now. She's almost certainly being sincere. It's her expressing her loyalty to you now.
I know it's hard trying to separate who they are now compared to what you know they were capable of then. I know because I'm still struggling with it, too. I have very few complaints about how my wife is handling herself in the wake of her infidelity, but her difficulty in understanding my difficulty accepting that she's changed and likely would never do something like that again does bother me sometimes. I hear "just focus on where we are now" pretty often, which does lead to some distress for me because it feels dismissive, but I know she means well.
I'm not shy about sharing my feelings about it, tho, and she's at least receptive, willing to have the conversation, and is doing her best to understand. For me it was only a year ago, so we're in quite an earlier stage in our attempt at recovery right now.
This shit ain't easy. Infidelity sucks. I know my wife was clueless as to how damaging her actions and words were going to be while she was in the middle of her affair. She's getting it now, tho. I could totally see her saying something just like what your wife said in a similar situation.
Just yesterday we were talking about some of the rough patches in our marriage. My drinking, for instance (sober over ten years now, for the record). She said, "and I stuck by you through it all," to which I said "Yes, you did. You stuck by me through a lot. Right up until you didn't..." There was an awkward pause followed by "I'm so sorry."
At the end of the day, I know she's more willing than ever to stick by me through pretty much anything now. I know she'd stay nights in the hospital with me if something were to happen. I know she would. I try to think about that, the now, instead of then. Easier said than done sometimes, I know, but I do sometimes manage to get out of the spiral.
[This message edited by Pogre at 4:45 PM, Wednesday, April 1st]