Space is so limited in assisted living that I'd go with a lap quilt. It can be folded on the end of the bed when not in use.

Unless she's already using a walker, I would not do this. My mother is 88 and still gets around without a walker or cane. She would be quite hurt, if given a gift "for when" she can no longer walk. Please give a gift, she can use now.

Small wall hanging, or pillow for her bed. You are so sweet to do this for her!

If she is in a wheel chair, a tote would be nice. Pillow cases, table runner, mug rug, small wall hanging, even a simple lap blanket would be a comfort.

I would send, or better yet, bring her flowers with a hand made card. If you are fortunate enough to maintain a relationship with her, visit her and bring samples of some of the projects you have made with her machine. You may then get an idea of what she likes and needs. If you can't visit her, then pictures of your projects and the story behind them or information as to the technique or choice of fabrics. If she enjoyed sewing as much as you do, she will enjoy hearing about the things you are making and that she can no longer make.

I was thinking of an arm chair over the arm organizer. It would be great if it could later be adapted to hang on a walker.

You didn't say what type of "seniors' home" she's moving into...independent living, assisted living or a nursing home...and that makes a difference in the choice of gift. I like the idea of a fabric box although a covered one would be nice...maybe large enough to keep photographs, cards and letters, a crossword puzzle book, a magazine, or other treasures close at hand but out of sight. It wouldn't have to be as large as these though. If desired, you could make a top in the same way, but with shorter sides and a very slightly larger base.
http://www.sewcando.com/2012/03/quil...orage-box.html

A tissue box cover or bookmarks would probably be used often, too, and remind her of your thoughtfulness.

Thanks everyone for these great ideas!
I have already asked the person daughter's if her mother would like to get some pictures of my little ones wearing garnement sewn with her beloved Bernina. The daughter had told me that the sewing machine was used by her mother, and later herself and her sister to sew many clothing (prom dresses, first interview suit, etc.) She told me her mother would love to. But I got later the idea of sewing a little something for her too. I don't really now where she is living right now, but her husband is still alive and she was herself in good health. All I know is the house was sold and they were selling also most of the furniture.
So I will make her a nice handmade card, put some pictures of my kids and add a little fabric box/wall hanging/mug rug (can't decide right now, it all seems good idea). She wasn't a quilter, so I think anything "quilty" will be new to her and she may like it.
Thanks a lot again for sharing your ideas!

OLDER people are always chilly when in a nursing home or anyone else's home. I would make it anyhow. She would love it.

Also, if she uses a walker a caddy for the walker so she can carry things around.