A strong set up and a good start to what will hopefully be a lengthy and interesting fic. I much prefer Gwen to MJ so any story where she lives is more than fine by me. :)

One minor (possible) nitpick - you said at the start you were going back 35 years. Not sure if that meant you were going to set the story in the 70s, but if you did, they likely wouldn't have cell phones. That very minor mention aside, this first chapter was well written with plenty of detail, introspection and reasoning behind the AU point.

I must ask though - is Sins Past in continuity here? Or are you discounting that particular storyline?

Loving this first chapter already, the fact that your allowing Gwen to live is a huge factor for my loving this fanfic already.