If she is really telling the truth, that she would leave you and her marriage vows given the chance, then I don't see how that would ever qualify as repentance of the affair. I am not a priest, but that statement seems to cancel out making a valid confession.
It would be like me confessing to theft, but telling the priest "If I get the chance, I'm gonna steal again and I'll be happy to do it."
As for zizki1974's question...
No, the Church doesn't expect a spouse to stay married to someone who has already left. But neither do two wrongs make a right. The OP is trying everything that he knows how in order to heal his marriage and give his wife another chance. They are doing Retrouvaille this coming weekend, and he is praying for a good result. Lots of us are praying for him, too. Let the Holy Spirit work where He will, and let's pray that his wife does see her mistakes and repents, and returns to work on the marriage with the OP.