Perhaps talk to the home manager. What are her interests and hobbies? It might be helpful to make a list of ideas for when you are not there in the future. Here are some ideas off the top of my head (depending on her disability of course):
Art and craft projects
Reading or writing
I sympathise as my Mum was in exactly the same state a few years ago. She died over 3 years ago thank goodness as how she or I would have coped in the present situation I dread to think. (She was almost 100). I too visited her every day.
Sound gives company and passes the time so:-
A radio with earphones which is set to a station she would enjoy and which she has to just press one button to put on?
Has she a TV in her room, even if she can just listen?
Audio books which a carer could set playing for her? (CD or tablet).
Could she see enough to try a large piece jigsaw with not many pieces?
Post her a daily letter in large print. Maybe some vividly coloured cards?
Some of those small tubes of handcream with different scents.
Has she got a cuddly toy? (My mum had a teddy she cuddled and talked to.)
Does she worry about time? Talking watch or talking clock. My mum had both.
Some of those overlarge playing cards if she could still play patience?
Would she like some children’s colouring books and crayons with big enough outlines for her to distinguish?
I feel for you and your Mum, I really do.