There are lots of options. What colors, styles, and things does she like?

I agree with the above posters! I would ask her what color she would like on the walls, bedding, and any other accessories.

I would let her take the lead on how she envisions her space. It could be a fun project for you both to work on together.

Here are some inspirational ideas:

Kids Bedroom Modern style · More Info

Teen Rooms · More Info

Port Streets Home · More Info

Country Club Project Remodel · More Info

Frisco, TX Home · More Info

Adding a few small touches may take her where she likes, then. Try new bedding that is multicoloured, and a few throw pillows to pick up favourite shades.

Move the mobiles to either side of the headboard, and place a bedstand and lamp under the shorter one.

A beaded curtain at the office door can take the place of the Christmas lights for shimmer without the exposed wires.

Some tabletop storage is needed, and from what I can see, some cabinets ( look at Ikea) under the desk would help, too.

Some patterned sheers will soften the window (and diffuse some Christmas lights hung behind them!)

One other thing - that Target chair looks a wee bit low, so perhaps mobiles hang on the right and this goes on the left:

Did you finish this room? If not, I think it's a simple fix. Add curtains and replace the mirror above the dresser with a white wall mounted one.