Given the bed and night tables, I'd suggest a Roman shade/blind instead of curtains.

I would agree. It looks like the window doesn't have much depth so you could do an outside mount shade that sits on the trim work and follows the width and height of the trim. Roman Shades, Honeycomb Shades, or Woven Wood Shades would be nice options in there.

Because of the placement of the furniture, I wouldn't do drapes. I would suggest an outside-mounted Roman shade. To elongate the window, I would go at least 6-12" above the window.

Hey There: You can go with a standard size roller shade or other style and install it to the outside or the window - an inside mount is really not needed. You might want to motorize it but for sure have it cordless for child safety. And if you want / need it really dark in your bedroom - black out fabric and the theater setting tracks will keep all the light out.