The ring is a matter of debate - some say leave it on, some say take it off. I personally took mine off when it began to make me feel worse - I could not function as all I thought about was my H. But it is a very personal decision. Don't do it to get any sort of a reaction out of your W, just do it for you.
I think you are on the right track with being friendly, but setting boundaries. She might be acting friendly b/c she has now filed, so feels safe doing so, so try not to read anything into it. That's not to say that things couldn't change, just be aware.
Good luck, Nicola
Life isn't about finding yourself; it's about creating yourself My thread: Trusting God's Plan