You don't need to look like you've moved on. You need to appear like you aren't sitting around thinking about her all day. You need to look like you are capable of living your life with or without her.
As for MIL, the more positive interactions you can have with people around your W, the better. Your W won't listen to you right now. But she may listen to family and friends. Treat them well. But when around them, act as if!
