I think this friend of yours is nervy. If she were any type of friend, she should have asked first before buying this. No matter how, small it may be.
When you visit with her arm yourself with the basics of what you were planning to take, look at the box.
Tell her, that you thought you would be able to squeeze her in sometime in the spring, but unfortunate, you won't be able to.
You have arthritis, and this slows you down a bit. Offer the items to her, and show her how it is done.
This way your off the hook and she can do something for herself.
I disagree with the sight as being a downfall. I am farsighted and wear 2.5 readers and use a magnifying glass that hangs around my neck, when I need it.
I also have a friend who is Blind. She was born that way. Let me tell you, she cooks for her and her partner, she KNITS. She visits people in Hospice. She does just about anything, a sighted person can do, not as well, but, she tries. No reason your friend could not try