For a window that small, you could get a custom window covering for hardly anything. Because it is in the bathroom, the most moisture-resistant options are: faux wood blinds, solar shades, and even faux wood shutters. But if you're not worried about water touching them, you can pretty much do anything you want. Here are some bathroom pictures for inspiration:

http://www.selectblinds.com/fauxwoodblinds/2-inch-premium-faux-wood-blinds.html

http://www.selectblinds.com/bambooshades/woven-wood-good-housekeeping-woven-wood-shades.html

For more bathroom ideas, check out this buying guide: http://www.selectblinds.com/bathroom-window-coverings.html

Good luck!

Lace/cornstarch window treatment! Add lace to your window with cornstarch. Iron your lace and cut to fit. Mix 2 tbsp cornstarch with about an equal amount of cold water, then mix that in about a cup and a half of boiling water. Paint a thick layer on the window pane. Then apply another thick layer on top using random brush strokes being sure to get all the corners. To remove it, you just wash it off with warm water.

Is the window already frosted? Do you want a warm look ( curtains) or a cold, harsh, scary look ( blinds)......:) ?

A blind would look nice there ,plus a fresh coat of paint + new towels .

Madera Falsa 2-Inch Faux Wood Blind · More Info

If the sink is still good keep it it will give you the retro look

Craftsman Bathroom · More Info

There are TONS of DIY tutorials for DIY roman shades on Pinterest. Check them out!

a cabinet for storage perhaps!

east side bathroom · More Info

change out the glass to glass panels used by stained glass artists, you can have fun and add some color-or use a white/clear streaky variety-see if there's a stained glass artist in your area that could help.

talk to the window covering pro who commented above!

Here are all our shutters: http://www.selectblinds.com/shutters.html Just put in your measurements in the blue quick quote bar and update. The prices will adjust accordingly.

We put in your window's measurements, and they're all available in that size. If you're looking for the most budget-friendly, the Express Faux Wood Shutters are the most affordable. http://www.selectblinds.com/shutters/express-faux-wood-shutters.html

If you're not sure, you can order free samples to see which one will work best in your space.

Good luck!

Since you are replacing the sink, can you turn it to be on the wall to the left? Seems odd to have a sink without a mirror above it. I'm not certain of the sizeof the room, but then you could put a pretty patterned element over the window. Personally I'm a fan of white wood blinds with a valance above it, on the wall to give the illusion of a bigger window. Once you figure out the pattern on your curtain, take your cue of that fabric for wall color.

I had the same problem... so I replaced the glass with a

I got my shutters at Home Depot...they were inexpensive and I love them :)