What should I take an elderly friend who's in a nursing home?

How about a plant wrapped in Christmas wrapping? Something hardy like a philodendron that will last and bring her pleasure. Or a book on tape or CD if she has access to media players?

Space is always an issue.. If you don’t know what she needs or has how about her favorite foods. I am certain nursing home food is lacking. A word search, or sort of time waster if she is not crafty.
A really comfy bright or pretty blanket or sweater.

How about some lovely flowers to cheer the room or like @janbb suggested a plant.

A hardy plant in a pot that would need little attention. A card holder could be stuck in it, saying, simply, “Love, Aster”

I vote for lovely flowers. Dialysis zaps your strength. I’m sure she’ll sleep many hours and the vision of seeing a bouquet of beautiful flowers would brighten her room and her day.

Flowers sound good. Also consider: what are your talents and strengths? For example, if you are a musician, you could give her a CD of your music or something like that, or if you’re a visual artist, you could paint her something.

I took her a big poinsettia but her daughter had already brought her one . It’s the thought that counts. She had mostly cards.
Turns out she wants books.

Well I can understand that. She wants something to do :) Do you know what kinds of books she enjoys to read?

No; but my daughter does! She was visiting at the same time and is close to Granny.