Monitor Windows Users Access to Shared Drives

I have a user that seems to be up to something in one of the network shares available on my network. Apparently this person has been curious what her other co-workers have been up to and is personally taking it upon herself to investigate. I want it to stop, but I don’t have proof of the activity. I’d like to be able to have a log created showing her activity on a particular shared drive (on Windows 2000 Server) with information that includes time and file (path) accessed. Is this possible without third party tools? Is it possible with third party tools? Thanks!!!!