Grandmas feet were bound, how to help if feet small for someone her height?

Small or deformed?: If her feet are just proportionally small, that shouldn't cause her pain or trouble, and there's nothing really to be done. But if she had full foot binding with broken or deformed bones, and her feet are now mis-shapen or painful, she should see a podiatrist or orthopedic foot surgeon who has experience with bound feet to see what options might be specifically for her feet.

A serious problem.: There were still women with bound feet when i lived in taiwan. It is now banned. It leads to permanent deformity & my understanding is that it can be quite painful. Binding is very damaging to the structure of the foot. Although the binding can't be "undone" an orthopedic surgeon might be able to address specific problems arising from the binding.