If she's wearing a hooded sweatshirt her boobs are not going to be that defined. Take a look at how the fabric lays over her chest in the reference you posted.
Those extra edge loops don't define a silhouette really. You can easily take these out and lessen the polycount. There's no reason to have them in there at the moment.
If you store a morph target then use the layer brush, all strokes will stop at a maximum height defined by the brush strength. See if that's what you're after.
Additionally, you may want to define the space between the barrel and the slide, as right now it looks like the slide's geometry is intersecting with the barrel. Reference attached: