If your mother is up to it, you should certainly celebrate her birthday, but that doesn't mean you need to shower her with gifts or goodies.
As you make
clear, there are very few things your mother needs at this point in her life. There may be small items that will provide comfort and enjoyment: a special pillow, a bottle of moisturizing lotion, a book on tape or CD, or a pretty shawl or bed jacket.
But if there's nothing material that she needs, there are other ways to honor her birthday. Consider putting together an album of family photos that she can keep beside her bed, for example. Encourage your children and other relatives to write poetry and make cards and drawings for your mother, and to call if they live far away. Offer to read to your mother or take her for a drive if she's up to it.
By far the best gift you and your family can give your mother is the priceless gift of your time and your love. Let her know that you love her and are thinking of her on her birthday.