I don't know about spinal taps but if it's anything like an epidural, I don't know how she could handle it. My wife had an epi before her c-section and it really bugged me. I'm not the squeamish type, either. It just seemed cruel. My back hurts just thinking about it.
Mike, the two aren't comparable at all. An epidural uses a very thin needle to deliver an anesthetic, which begins to numb as it goes in. A spinal tap uses a larger needle into the spinal column and the doc has to withdraw a full syringe of spinal fluid. It was unbelievable. The doc even said, "We could give you some darvon and a skin-deep anesthetic, but it won't make much difference." So she went ahead without any.