If you haven't already, try playing about with your sky settings (save your original Bryce file first), and experiment with moving the sun control about a bit. You're probably finding that the bits of your figure you really want to be seen the most(her face for instance) are being shadowed by the rest of her. If you change the angle of the sunlight you may come up with a better compromise. Alternatively you could move the figure, if you want to keep the sun the way it is. Also, more haze in the atmosphere setting will have the effect of lightening shaded areas without upping texture ambience. If she was done in Poser with a default skin texture, spending a few dollars on a decent set of textures should improve her realism. If you have already got a good texture on her, it may be that the high ambience and the bright radial light are leaching all the detail out of it.