Agree with the other posts, don't say a thing. It'll only plant the idea in her head and that will drive you crazy.
As to you concerns about not having children, that was a significant concern of mine and I was quite envious in some ways of others who had kids that could use them as a reason to communicate. In other ways I am very glad that I don't have kids to drag into this roller coaster. What worked for me was the mail. H moved out and I would send him his mail. A couple times it was just that, I would package it up and send it, no note or anything. After he was willing to talk with me I would use that as an excuse to get us out of the public eye (usually a coffee shop) to see if I could spark any convo. I would not initiate mind you, but it would give us a moment without prying eyes. You do really have to relish every moment you get to try and shine. Do not start R talk. Keep any contact light even though you will not feel happy.
My first meeting with my H was after 2 months of being S. We really had minimal contact, mostly really awful email fights, no phone contact and definitely nothing in person. I too was concerned with how he was going to see my changes. Trust me, they will if the change is sincere and better if it can be drastic. When we met I coached myself to be happy, smile, act confident, do not talk about R. I even prepped a bunch of non R things we could talk about. I made sure I was in charge of the conversation, even though I let him do most of the talking. If there was a lull I kept it moving so it wouldn't drift into negative talk. If your W is observant, she will notice. Then the trick is to keep the changes going.
Good luck and keep posting.
Me: 37 H: 35 M: 6 T: 8 2 cats, 1 dog, 0 kids S: 09/10/07 D started 9/21/07 (I stalled) Piecing: 11/9/07