My choice would be to hang a rod at the same height as the bookshelves and use rod-pocket panels that skim the floor. I'll poke around and try to find a picture :)

This isn't a perfect example because it's a bay window, but it is a similar look to what you would have:

Valences? Valences are always ok

We have this area blocked off as our kids’ play room, so I don’t think having floor-length curtains are an option right now. Do you think a valance over a cornice?

Also, my husband is planning on building a window seat between the two main bookcases. Do you think a cornice or valance would still work or would it look weird?

One thing to bear in mind is that, when you open curtains, they will block out considerable light because there is no space between the window and the bookshelves. Combine that with not wanting flour length curtains and you may want to just have shades, or your blinds. You could have a cornice that lines up with the top of the bookshelves. That could hide shade hardware, or provide decorative fabric.

Yeah you could go around the top of the cabinets with a band of some kind. You could even throw some lighting back there

I’m not sure what you mean by a band around the bookshelves. Do you happen to have a picture of what you’re referring to?

You do not have space for drapes at the windows without having them sit covering 1/2 the window just do roman shades .

Cornices come off as dated. I think Patricia Colwell Consulting's suggestion for roman shades will allow for more natural light as well as softening your windows.

Add moulding above the windows at the same height as the shelves and stain it to match the window and shelves :)

I was going to suggest what sillycannoli suggested - roman shades mounted flush with the top of the bookshelves. This way when they're pulled up, they will block just the wall above the window and not the window, and will give the illusion that the window is bigger.

These are such great ideas!! Thank you everyone!

This may seem like a stupid question, but I was looking up how to make Roman shades, and it looks like it would take the place of the blinds. We still want to keep the blinds, though. Can I make Roman shades that are the same level as the top of the bookshelves, but only come down to cover the top of the blinds? I’ve tried to find pictures of something like that, but I can’t. Do any of you all know if that can be done, or if it would just look stupid if I tried?

Why would you want both? It's redundant.

Sure...why not :) They would be faux roman shades and would add color and texture.

If they just want the look, then just use a valance. Roman shades are not cheap.

The windows on the front of our house are so big, it’s like living ina fishbowl where the sun is roasting in the summer and it feels like our neighbors can see our every move, so that’s why we have blinds. I was given the advices earlier in this post to do Roman shades, so that’s why I asked about the Roman shades on top of blinds. So, you all think just a valance would be best to bring some color between the bookshelves?

Maybe a shelf across the top of bookcases with lighting underneath the shelf.

While the point about panels taking up a lot of the room is valid, I still think they are a great option for your situation. Allow me to elaborate lol

-they add the colour you want

-they pair well with blinds

-they are easy for kids to pull closed to remove glare from tv or add another layer of heat barrier to what you have described as a "fish bowl."

-they make a great place for a two-year-old to hide for hide and seek. (Not everyone will consider this a bonus but I do!!)

-you're spending money on something that adds practicality rather than just for show

Just my thoughts.

What if your sweet hubby built in more shelving under the window for the toys you already have there? Maybe with doors so you can hide certain things you don't want out. Keep it flush to the bookcases. OR, he could build a little desk(desktop with simple legs) extending right under the window so the kids can play/draw/study. Then above the window, he could also build a small shelf/case above the window that is flush to the current bookcases....so in other words, there is bookshelf/desk all around the window. I'd forget the curtains/valances, etc. What you have seems to be nice. Or hang some consistent artwork/wrought iron decorative piece in the area above the window to fill it in....

Faux roman shades are on sale (country curtains .com)