A paper lantern is not safe for a child's room. Are you trying to think of something fun or something functional?

I am probably not the one to give advice, but I went to ikea and they have very cute flower shape lights that hang on the wall. I bought three for her bed area, they give off a nice soft light, just enough to read stories by. What about a nice chandelier for the middle of the ceiling, there are some that are totally precious
and girly.

Red

Paint the ceiling like the sky, blue with fluffy clouds, and the hang large decorative butterflies from fishing line from the ceiling at different heights. You could faux paint some birds there as well.

I saw a model home once with a valuted ceiling for a boys room and it was decorated like the masts of a sailing ship. It was spectacular.

I'm not a mother (but I am an aunt to 6 kids) so I guess take my ideas with a grain of salt. I'd go with some sort of adult lighting which complements the space (perhaps one hanging fixture, or a row of them on the beam?) And, add in some table lamps to make it cozy. I would think the main goal would be to make it nice and cozy for a small child.

My view is that the decor should be functional and should not have to be changed out as the child grows. You can bring in the "fun" stuff with linens and other accessories, rather than getting a bunch of stuff a fickle child might not even like down the line (or appreciate at age 2 1/2) and which you'll just end up getting rid of.

Then again, I have never really understood decorating children's rooms or nurseries in strongly "child-like" or baby colors and themes. ;-)

Thanks to Cindyloo, maid o cliff, dgmarie and lizzie nh. All your suggestions are useful. I really like the idea of painting like the sky and I wish I had seen the room with the sailing masts. I very much appreciate the reminder to be safe for children. And lastly, lizzie, aunt of six!, you are right. Children do grow up before you know it and then you are "redecorating again. I posted this query for my daughter in law so I am sending these suggestions to her. If anyone is still following this, please note the apex of the ceiling is quite low so if we hang anything there it will have to be on a very short chain to avoid hitting grandchild's father's head. My apologies for my delayed response. I'm in the midst of a major remodel. Thanks you all so much for your suggestions.