more cleavage

That sounds a little silly to me. But whatever she wants to do, she should do. I try to keep my cleavage to a minimum, especially on days where I have to work or go to school (as I don't usually want to draw too much negative OR positive attention to myself, and I feel like showing even a little bit of cleavage at work is unprofessional) - but when I go out - to bars, casinos, movies, etc - I'm more likely to wear clothes that flatter my figure more and that may show a little (or a lot) of cleavage. I don't know why this is, but a lot of my "party clothes" are a little more revealing. It's not because I want a certain amount of attention from guys or anything like that, though.

I guess people's reaction towards this is would somewhat depend on their cultural background and the norms of the society they belong to. I live in Manila,the Philippine's capital. It's a very populated city and the center of almost everything. People are quite liberated and westernized as compared to other places in the country. You may get a few stares if you decide to show off some cleavage at the mall or at a bar. But if you do this in a small town, people might be scandalized and find it appalling.