Law school is helpful in that it creates the basic foundation you need to understand how the law works and how to apply it. Law school also teaches you how to identify the issues, cut through all of the noise, and figure out the solution to your clients’ problems.
I would not be the lawyer I am without law school. I got a very solid education which gave me the foundation I needed. When I left school, I had absolutely no problem interviewing clients, identifying their issues and determining whether they had a case. The fact that I took a clinic was very valuable as well. My business knowledge, however, came from my work in a nonprofit after law school. My practice legal knowledge came mainly from watching and talking to other lawyers.
When I left law school, I was able to handle a small trial on my own, but I only had the confidence to do so because I had been in court through clinics I had chosen to take in my final year of school. Law school does very little to prepare people for the business aspects of law. I would say that law school is much more about the theory than the reality of practice.
That said, if you have the solid education provided in law school and you are willing to study and learn from other lawyers, you can build a practice on your own and get the practical experience you need while you are on the job. As long as you do not reach beyond your limitations. I.e. someone right out of law school should not be handling a death penalty case or a medical malpractice case. But she certainly can get started with some basic cases in various areas and work her way up from there.