The big question is in what style she'll be redecorating this room in?
Does she know yet or is she hoping this will be the deciding point in how to do the rest of the room?

It's all still up in the air. The house is updated-traditional (is that a thing?) and she's thinking of using sage green as the main wall color. She likes pops of color and is open to doing something different/dramatic. The bathroom is getting totally renovated, so the bedroom needs to look updated as well. If we come up with a great idea, it could end up being the deciding point for the rest of the room, otherwise we're more likely to try and "hide" it. Does that make sense?

I'd ignore it. I have two open spaces above my foyer closets, and I just pretend they're not there.
They're terrible dust collectors. You just can't see the flat surface. If I had decorative items there, I'd see the dust, and the little spider webs stringing from object to object, and I'd have to drag the ladder out and risk breaking my leg or worse, neck, and I'd be thinking about those little spiders and their babies....You get the picture. I'm no constructive help.
Dee

I agree with Pal, why do builders think this is an asset?

My mother's 80's townhouse has the same thing...I think it was that era's "architectural interest." I agree, drywall it in and then perhaps she'll have wall space to hang a very dramatic piece of large scale art.

Well if you're thinking of ignoring it before I'd close it in I'd check into have it made into storage. I know that sounds weird, but it would be a great place to store seldom used items such as Christmas decor extra bedding for guest room, things you might normally avoid putting in the attic or basement because of moisture or extreme temps. Just a thought.

I have had contractors do that too. If you line up the upper doors with the lower it looks relatively natural, or do doors all across.

It seems a very tall space to use storage efficiently--you'd need a really tall ladder to access the space, no? And if I were the OP, I'd be terrified that my mom (if she were stubbornly independent) would try to get up there herself.

It really is an awkward space. I have one, smaller tho, in the guestroom above the closet. I haven't put anything up there because as has already been mentioned, it gets dusty, and I don't want to have to routinely clean that area.

I could picture a very horizontal art quilt hung from the ceiling and falling just to the top of the closet doors. With maybe some neutrals but a pop of red or orange or even purple or teal for some brightness (well, not the last 2 if she really wants sage green!). Maybe one of you knows someone who quilts and could put together something very simple (Amish patterns are usually very graphic and simple; also look at patterns at FunQuilts.com.).

, I was thinking of doors all the way across as in a number of sliding doors.
PammyFay, you are correct that it could very well be a bad idea if the Mom isn't able to climb safely. It was only a suggestion for the OP to decide. Stevsie asked for ideas, I was only giving one I thought was a possibility. If Mom is healthy, and the OP gave no suggestion that she wasn't, then a sliding library ladder could make the area accessible. Though I certainly understand your concern. It is very legitimate.

Well that's strange. I had Pal before the first comma and it didn't show up. Sorry Palimpsest.

Oh, I would love to see lots of large black and white photos leaning up there. It can be a great space with the right stuff.

It was a mid to late 80's architectural phenomena. I have something similar in my bedroom. I've just ignored it quite honestly, and shudder to think how dusty it is up there.

The idea of having to actually dust things that I could see the dust on that high up was the deciding factor in doing no decor up there in my room.

At first I thought it would look really odd bare, but now I don't even notice it.

Funny, I am heading into a very similar renovation with a similar space. I was just building up the courage to post the space here.

I'm sorry I'm no help. Closing it in sounds like a good idea.

Beth P.