Please post a floorplan and pictures as describing a space doesn't convey enough information.

It is difficult to capture images due to the small space.

You might be able to find a shelf unit for between the washer and dryer. Narrow cabinets above where you have the ironing board are also possible. You do need to consider head space.

What do you need to store?

Here’s what I did in a small laundry:

There are uppers, and there is a shelf below. The shelf is just deep enough to hold the detergent, bleach, etc, so did not interfere with the washer lid.

The machines are pushed to one side, so the space by the wall hold the drying rack, a broom, collapsible hamper. There is still a little space in-between, where I have a boot tray. Why? Sometimes I have something wet from soaking that is not going into the wash cycle, at least not right away, or is something muddy from outside, and I just don’t want it on the floor. But I digress.

The ironing board hangs on the door and folds down. But, that means it is a little shorter than a standard ironing board. If you need a full size board, obviously you can’t iron in the small laundry room so yiu do it somewhere else. So the ironing board can live somewhere else.

I have a small hook rack on the wall behind the door, that holds the broom, swiffer, sponge mop, and above it is anohter small hook rack for shorter tools like a lambswool duster, bristle thing for the dryer vent and refrigerator coils, a flat felt duster-thing for under the refrigerator.

Not in my space, but in another, I hung shallow wall basket racks. Only a few inches deep, but perfect for hold things that might get lost in a cabinet.

For you, it all depends on what you need to store in your space. Maybe you have cleaning tools in another space. or maybe you need to keep small hand tools, glues and repair-type stuff in the laundry room.

Is it possible to move the upper cabinets all the way to one side, and add cubbies? Kind of like wine storage, for rolled up towels and cloths, or dryer sheet boxes, or something?

If the uppers are too high for her now, she won’t be able to reach onto the raised washer! Unless the drawers are pull-out steps.

I do love that idea but I struggle to get the clothes out of the top loader now. Shorty here😥

This is what I did (nearly finished). I seriously considered the LG Washtower but did this instead.

Looks good!

I was opposed to front loaders when I purchased but I am not happy with the top loader I have either. Now I am stuck needing room for the lid without the benefit of the space afforded by the front loader.

With a front load you have to keep the door open, or at least prop it open, so…

Yes, a front loader would be a better fit, but that's a done deal now. (Yes, you have to leave the door open a bit, meaning an inch or two - it doesn't have to sit all the way open.) You can find a narrow shelf unit to fit between the washer and dryer, and it can pull out for easy access. You don't say how big that gap is, but you can find "slim rolling shelves" that range from 4.5" to 9" wide to fit that space. Here's an example

BTW a washcloth in the door of the front loader is all tyou need and the new frontloaders do not require the door to be left open at all. As for your space I need to see a pic of the whole room . Waht is the must things tou need storage for ? Why do you have that space between the units that justcollects crap . Post a to scale floor plan for sure. Where is this space located in the house ?

Thank you, I can’t believe I didn’t think of that. I actually had one at my last house but got rid of it thinking I wouldn’t need it here. 😏

Oh, yes! or, an ”X-Narrow” elfa cart with wheels, drawers, and a top (although you could forgo the top and use the top shallow drawer as a tray-top, which would keep things from falling off between the machines, but if it is on wheels it is easy to roll out to retrieve and to clean.) and you can select drawer heights to accommodate what you want to store. Their 30% sale just ended, but there is another 25% usually in August and 30% again starts in December.

I had one of these in a wee kitchen with exactly 12” between freestanding stove and doorway, no other counterspace next to the stove, and that cart did it all. Now we use it in a kitchen with few drawers, and even got it a companion.