All the DAZ figures look young "out of the box". It's partly the quality of the skin rendering. The problem with Stephanie, compared to Victoria, is that she's short and doesn't have large breasts, both features we tend to assiciate with teenagers. I know quite a few adults who fit that desctiption, one of them in her fifties (and I just wished my body were in that good a shape). But what gives away her age would have to be modelled with texturemaps and bumpmaps, not, much, with the mesh.