My mother has the classic dementia lean in her chair. Does anyone know of a device that can be used to help keep her more upright?

I'll give my usual plug for a customized tilt in place wheelchair, even if she isn't wheelchair dependent now there will likely come a time when she is, and money spent on one now can save money spent on lift chairs, wedges and supports or other devices because a good wheelchair is designed for all day comfort.

My MIL's NH has a special insert for her wheelchair that comfortably props her up more. MIL broke her back in 2009 and is full of "scaffolding" in her spine, didn't rehab well and her musculature/core muscles are basically 0. The insert helps a lot and eases her back pain so we can have longer visits with her.

Creative use of cushions will help in the very short term (i.e. today, now) but as your profile states that you plan to keep your mother at home forever it might be worth investing in a specialist chair for her.

I googled 'posture support chairs' and found what I was looking for, but it took a while - you might do better to search specifics, such as "specialist chairs for stroke, cerebral palsy and dementia."

Anyway. The point is that there are, out there, chairs which are adapted to relieve pressure and correct posture in people with a very wide range of disabilities and care needs. Suspiciously, the search results are very coy about prices which leads me to suppose that good ones are dizzyingly expensive. Still! - you can't know until you've looked, so I should have a look.

You will probably find all sorts of pressure-relieving cushions, too, at any reputable mobility or disability supplier; but do bear in mind the general rule that you get what you pay for.

I do not know but will bump up your question so you can receive help from others.

I read your profile. So, it looks like you took mom home due to Covid. Was Covid in her facility? Can you provide more information please?

How did they tend to her in the facility?

Best wishes to you.