What window treatment would work best here?

I see your dilemmas! Vertical blinds like what existing are an option, long curtains to work with the height or window film to skip kids getting caught. Try a Pinterest search for other options too.

Besides using verticals, or drapes, I would go for a replacement door that includes the blinds inbetween the windows.

You could use curtains or drapes. Hang the rod high and make it long enough so they can be opened and rest at either side of your slider when opened.

In my front room I hung a double rod. One layer for hombre sheers and the second for black out drapes.

This gives me the opportunity to have some privacy during the day by keeping the sheers closed or total privacy at night. To be fair our front window does face the street.

We have pets so understand the need for drapes that don't become a jungle gym.

Purchase washable drapes with rings included in the header and pull all to the left side for easy access to the outside during the day, then pull fully closed at night for privacy.

Build a valance about a two feet wider than the glass doors to hide the vertical blind rail. Hang curtains within that foot on each side using tension rods. You can let them hang down straight or use tiebacks. You can paint the valance or upholster it using same fabric as the curtains.

.Similar situation at our house, without kids. We hung blackout drapes from Walmart, they do a good job of insulating from the afternoon sun. If you leave your door open and close the screen, I had a problem where I walked into the screen-more than once. To solve that, I hung a piece of yarn from the top of the screen, just enough to prevent future collisions.

Hello Olena, hope this idea helps you out, I think they are so cute!

https://www.selectblindscanada.ca/panel-track-blinds/?id=22&productId=1054&gclid=Cj0KCQjwn4qWBhCvARIsAFNAMigKRfYRCaNjA7MGCtnH9fbRP_T0JiRifoneSiuhiW_pUuD089SOIr0aAsAuEALw_wcB

In this case you could employ draperies or curtains. To allow them to be opened and rest at either side of your slider when opened, hang the rod up high and make it long enough. Or I would choose a replacement door that includes the blinds in between the windows rather than utilizing verticals or curtains.

What will be the main function of the window coverings for this patio door?

Are you needing privacy after dark so that others can not see into the home?

Are you needing to keep bright sunlight out during certain times of the day?

Or, are you wanting some kind of fabric for decorative purposes only and to soften the look of the room?

lI would just put some sort of topper on the top and not worry about curtains especially with kids going in and out etc.

https://www.homedit.com/curtains-for-sliding-glass-doors/

I would go with a valance but raise it higher so that it barely covers the top of the casing.

The slider could really use some trim to break up the expanse of the wall color. Add a colorful curtain and rod to liven it up.

With your patio 'window' having an opening door, the problem with curtains is that they catch in the wind and are often sucked outside when the door opens. Besides being frustrating, the fabric tends to get dirty fast. With children in the home trying the fabric neat and clean is often a losing battle.

As it is privacy after dark that you are wanting, I would suggest that you check into the panel track blind system.

These panels are hung individually, but are wider than, and do not pivot like the old verticals. You can adjust them to cover all the window, or partially, as the panels slide behind each other when they are in the open position. They can be mounted on the ceiling or on the wall, and are available in different colors and patterns.

Here are some examples:

Hi Olena: You will need something that will take the traffic of the kids. Here are some pictures that I thought might work for you. Right click on the image and choose 'open image in a new tab' and it will go into a new tab that you can open and see the picture larger.

The whole wall thing might be good as you can pull the curtains back to expose the entire window to keep an eye on the little ones.

I like the mantel look! :)

The whole wall, only pulled to one side and it looks like it's attached to the ceiling.