For anyone who has suffered (or, is suffering) from backpain or is knowledgable in that area, I have a question (details inside)

My sister was in an awful car accident three years ago. She’s a RN (used to work in the OR), but, has been unable to work due to the accident. According to the specialists, she has suffered a bit of brain damage (she has difficulty with concentration), she can’t grip with her left hand and she has been dealing with excruciating back pain. She’s had three years of doctor’s appointments, physio, and psychological therapy and finally today, she got the results back from her MRI. The results showed severely herniated discs in L3, L4 and L5. The neurologist has put in a referral for surgery ( my sister: “which I’m NOT having”).

I’m trying to understand this. How exactly would that type of damage affect her (pain wise)? Is surgery risky? Could she become worse. if she had surgery? According to her, surgery is a definite “no-go”.