Every marriage is different, and people can have a change of heart. There is nothing wrong with repairing what's broken. Maybe she misses you, your friendship, the things that caused her to initially fall in love with you. Perhaps it is a trap (but to what extent? What harm comes from a walk, or a level headed chat, or lunch?) Perhaps you desire no more of her or the old life. But keeping the door open can certainly have its benefits, too.
I'll use my personal situation as an example. Our separation began in October. We filed the divorce paperwork in April. We sold the house, and she moved back to Michigan with the kids in May.
The court rejected the divorce, not enough time had passed. We've yet to re-file.
I'm traveling regularly to Michigan to visit, and stay in an extra room at her house. My second to last visit, she admitted she no longer wants to divorce. My last visit, we enjoyed a nice meal out on our own (that's the first time just the two of us were able to dine without the kids since before we moved to Kentucky 4 years ago...probably a big piece of the problem!), and we returned to intimacy.
We talk or text with each other on a daily basis.
I attribute this to the fact that we have removed ourselves from the martial stresses that were leading us to divorce, and now we are able to enjoy the friendship that caused us to fall in love initially 28 years ago.
I don't know that we will necessarily return to the marriage as it once was, but it's great to have my best friend and lover back.
Anyway, I say all that to say this.. maybe rethink that invite. It might just be a cracked door that opens up to an amicable solution to your situation. But as I said, every marriage and couple is different.
God bless, and good luck.