A lot of it depends on where the herniated disc is located. I had a bad disc at the C6-7 level in my neck. It was so bad I had no feeling in my left arm and was basically in constant spasm and addicted to vicodin. I tried chiropractic and physical therapy but nothing helped.
I had the surgery back in 1996 and the relief was instantaneous. As soon as I woke up I could feel my hand and had my grip back. I was in the hospital for 3 days. I actually had more pain from the spot on my hip where they took the bone graft then I did in my neck where they did the surgery. The surgeon made the incision on the front of my neck to avoid as much trauma to the spinal cord as possible.
I did have to wear a scary looking neck brace for 4 months and it took about a year before I had my full range of motion back. A lot of it was my own fear--like not trusting that it wouldn't hurt when I had to tilt my head back when getting it washed before getting my hair cut. Now I am fine and doing everything I could do before.
I am sure she will be fine, but remember a lot of it is the mindset she approaches it with. I KNEW it was going to be successful and decided that it would all be fine once it was over. She has to take an active part in gaining back all the motion she had before. It can be done.
I injured myself ice skating. I fell while attempting a jump. I knew I was fully recovered when I landed that same jump almost one year to the day after my surgery.
Best of luck to you SIL. Keep us posted.
Linda