Her offer reflects the great job you've done with unconditional support, detaching, and staying positive. I'm sure that didn't all come about or was present all at the same time, but you stayed at it, and she noticed. As we've seen, the dating world has its share of disaapointment, and the WAS is going to see this if they are attending with any amount of truthfulness.
Anyway, regardless of what happens and what you decide, I hope you can pat yourself on the back for a job well done.
By the was, a FF here warned me about the possible timing of a 'let's try again' offer by a WAW that is merely intended to break up a new R the LBS is starting with someone else. Not that she's doing that, but I'm glad you're staying a bit cautious.