Your little girl's room is just darling. I love how you've made her name so colorful above the window... it picks up the colors in her bedding.

One thing you might want to do is put some window film over the top of the window, above the existing curtains. You can get ones that look just like a stained glass window. Or, you can use a sun blocking film, if you prefer.

Another thing you can do is paint the upper part of the window with Gallery Glass, to create your own version of a stained glass window.

A third option is to do this, only instead of doing it with a valance, as pictured here, attach full-length curtains this way. Then use tiebacks to open them, and unhook the tiebacks at night to close them, similar to what you have.

They also make arched window blinds (http://www.burmeisters.net/missy.htm). I am not recommending that source... it's just the first one I found.

Here is a link you might like...

Here is a link that might be useful: Arch window treatments

My parents had a house with a window just like that in the living room. They wound up getting an arched fan blind (didn't open and close) to fill in the upper part of the window and regular blinds below. I think it was Duette honeycomb.

thanks,
these are all great ideas. I wonder if any come in black out to block all light?

I have two windows like the one you pictured--one is in the dining room, the other is in our guest bedroom. Both windows face west, and get full sun exposure all year. I first had a sun-blocking window film applied, then I put arch window blinds in each window (like writersblock's parents). There was still too much light in the bedroom, so I cut a piece of blackout drapery lining a little larger than the arch window, and stapled it to the inside curve of the molding. Instant darkness! I did have to add a curved drapery rod with a sheer curtain to hide the blackout lining, but it solved the problem. HTH

I think you can get the honeycomb shades now in light blocking materials, but you'd still a problem around the edges.

I purchase custom, moveable arch shades from this company:

http://www.adjustaview.com/

You can get them light blocking and the ends sit in a track so the light doesn't leak around them much at all. I liked them because they open and close.

They are not, however, inexpensive.