My mother has arthritis and neuropathy, but she is not sold on the idea of medicinal cannabis...

"What would be a good way to bring up the benefits of medicinal cannabis?"

One way would be to start with a topical CBD salve and explain to your mother that as long as she does not touch her eyes or mouth, washes her hands, and does not take a steam bath with it on that she will not have any cannabis in her blood stream. In this way, she will not get any altered sensorium or "high" sensation.