Small changes add some mystery... the new clothes and cologne. Maybe change up some of your routines a little bit, do things differently than you usually would in the evening. Remember... spontaneously going out for ice cream? Be on your blackberry more than you normally would (even if you are just fiddling with it, she won't know... she will be wondering who you are in contact with). I did that, and it definitely made my H curious. Another time I was actually on these boards and H was in another room. Someone had posted something funny on my thread and I laughed out loud. H came into the room with a funny look on his face and I could see he was dying of curiosity. I gave a vague answer. When H was working late, I'd be (uncharacteristically) out with the kids rather than waiting at home. We would go do something fun, and he would express sadness at feeling left out. One time when he came home late, I had different music I don't usually listen to playing...
Just things like that will make her wonder "why the changes? what's going on?" It will unsettle her. The WAS counts on you being the same, being available, being the "constant" in their life, the "fall back" plan. When you shake that up, they have to take a second look at things...