I had the surgery on my right hand about 5 years ago and I don't know why I waited as long as I did!! I haven't had any problems from CTS (in that hand) since.
Most folks don't have any problems after the surgery, but I would say between 10-15% may still have issues. It depends on if there was permanent damage to the nerve, and unfortunately, there is no way to know that.
Anyway, I had the surgery on a Thursday and was back at work on Monday although I couldn't drive for about two weeks. After surgery she will not be able to use that hand at all for about two weeks and the stitches will be in for about 10 days. Think of it like a "torn" ligament...it takes awhile to heal. Essentially the surgery cuts the ligament.
It will take about 5-6 weeks before she'll start feeling "normal" again. Although there will still be some residual pain/weakness. I didn't do any physical therapy because my doc felt that you know your body best. He told me don't overdo it but don't "baby" it either. I was told to use it as much as I could and rest it when it hurt. But each person is different...
Does that help?