Yup, be nervous, be cautious. Do not act overly excited and get mushy on her. This could play out a number of ways and yes the turn around seems faster than usual.
Don't want to rain on your parade but you may discover in a few weeks that she still has other guys, they are just better hidden now.
It is possible by your going almost directly to the Last Resort technique that you stopped her in her tracks. That would be great, but don't blow it by coming her way too quickly.
Maybe she proved her point, made her statement, blew off some steam. Now that she feels she got your attention or got "even" or whatever she was after, now she is ready to settle down and see how it goes with you and your changes.
It is also possible that she got out, got a taste of the wild life and then realized that you were her security blanket and came back. Be prepared for her to go into cake eating mode. She is with you for stability and then when you turn your back, she is running wild.
Too soon to tell which but be wary, be cautious. DO NOT start waving your victory flag yet.
I've seen stuff in worst situations than yours turn around in 6 or 8 weeks so it IS possible but it is not common. Here's hoping you are one of the lucky ones.
Me 44 She 46 S13 D9 M18 T23 3 years DB'ing Successfully busted
