A gallery wall of pictures would be great in her bedroom. On the side walls and not over the bed (so you can see them).

Lamps for bedside tables. Can be matching or not.

LOVE what you did - the room looks great! The only thing I feel is missing is a shot of color (blue would probably be the best choice based on the existing decor) and some artwork/personalization. The gray colors create a great neutral background and I like leelee's idea of the gallery wall.

One thing I will say, from one mother to another - I re-did my daughter's room when she was 16 also, and as a designer of course I wanted it to be "just right." But my daughter wanted to personalize it with some posters and other items that did not, let's say, fit with my design sensibilities. You may run into the same thing ;). But at that age I think it is important to give them a little bit of leeway to personalize the space even if it doesn't fit the "design" :)

I agree with the aqua/blue lamps and maybe a matching pillow.

A nice artwork over the bed with a hint of white and soft turquoise would compliment the room.

http://www.artspacewarehouse.com/size/above_bed_art_gallery.html