Without knowing exactly what your mother’s problems are, it would be impossible to give a realistic suggestion that your mother can use. A lot depends on what type of arthritis your mother has, where exactly in the foot it is,and if anything has been tried before.
In some situations, people with arthritis in the foot do well with special shoes or inserts in their shoes. Others do well with surgery. It’s important to discuss her options with her doctor and, if needed, a surgeon, to see what can be done.