My mum is writing on the walls. She has Alzheimer’s. Any advice?

Look up washable paint. Some are very good and really work well.

Better still, apply dry erase paint to her entire walls:
https://www.amazon.com/Rust-Oleum-241140-Erase-Brush-White/dp/B000PGBCOC
"Dry Erase creates a unique writeable-erasable surface for walls, doors, cabinet doors, message centers, menu boards, toy chests, easels, and craft projects."

If you apply dry erase paint to the walls, give your artistic loved one the dry erase markers so she can have a wonderful time creating.

Your profile states that mum is in an assisted living facility. Have they said something to you about it?

They most likely will paint the walls before a new resident moves in. I wouldn’t be terribly upset by her scribbling too much.

If you want to clean it, ask the staff what products do they recommend to use.

We have a product here called Mr. Clean Magic Eraser that works very well. I don’t know what products are in your area.

Hard for your walls, but I love your Mom's creative streak!

I kind of miss the small doodles my toddles made now.. of course at the time I was horrified & had to teach them to wash it off & where it was appropriate to draw. Makes me wonder.. if I'd let them loose.. maybe they'd be 'Banksy' artists by now...

What about washable markers? There are specific window markers too - any windows she could safely decorate? Or restrict to writing on just ONE wall?
If she would, there is blackboard paint - then supply chalk.

Has Mom always been creative? I'm thinking a senior daycare art group?

An unique problem! But, like many things in dementia-land, if understanding consequences is diminished, more supervision is often needed.

If mom is enjoying herself scribbling on the walls and you don't mind, then there's no help needed. Don't fix what isn't broken.

If you don't want mom scribbling on the walls, move her away from the walls or take away the writing instruments she's using to scribble with, replacing the 'walls' with a large pad of paper or a chalkboard or dry erase board. But moving her chair or bed away from the wall would be the best idea.

It doesn't sound like your mother needs help, per se, because she's scribbling on the walls. Unless you feel she's upset or agitated, then call her PCP and chat about what you feel is going on. Calming meds are usually available to dementia patients who need them, but again, scribbling on walls doesn't sound like agitated behavior to me.

Best of luck.

Smiley97, with Alzheimer's a person is slowly going back into time. Eventually they could develop child like actions, such as writing on the wall. Is there anything else child-like that your Mum is doing?

Unfortunately, there isn't much one can do to stop this except wait it out. This phase will pass and something else will take its place.

Why don't you put up some chalk boards around the room(s) where she spends most of her time, that way she can scribble to her hearts content?
She may also need more round the clock care, meaning someone who can better keep an eye on her to make sure she's not doing things she shouldn't be.