Everyone else is right. Truth is the best option. Let her bring it up. Enjoy your friend. Don't sweat too much about what she's going to think because trying to get in WAS's head is a bad idea (take this from me, I was trying to live in that place and the lighting is really bad, not to mention the furniture).
You keep doing what you believe is right, the things that let you know when you look in the mirror that you're doing your best to be the guy you want to be and to treat your W the way you'd want to be treated. You have a great handle on things so far... and we're all pulling for you!
