Pain after spine surgery. This issue?

Hello Doctor My mother is 56 years old her weight is 85KG and she has Thyriod, sugar, BP issue . On 2nd May 2025 she had spine surgery for L4, L5 and S1. Even after 12 days of surgery she is still having numbness in her right leg after surgery and having pain in whole right leg whenever she tries to sit or walk for few minutes. She feels like legs are heavy and doesn't have much strength in her legs to walk . Shin bone area also became sensitive and pains when pressed little bit. Surgeon who did the surgery said that it will go away after few days and suggested to walk more. Could you please tell me that is it common to have this kind of pain and numbness after surgery and how many days this pain or numbness can last? Can we do Physiotherapy/ apply Ice packs ? What's the best solution for this issue ? Please suggest