Like someone already said, Secretary is a Director...small company probably has no policies or similar in place. Hell, no offense to Jock, but the I.T Manager has been appointed because he knows a little bit more about technology than the rest of them.
First thing to do with is speak with the MD and ask them about an ICT Policy and or Internet Use policy. If they don't give a monkies go back to your day job and don't worry about it. If he does care then explain to him about torrents and what it is doing to your company bandwidth let alone the risks it can have on your network. Let's not forget to mention if any investigation is had with downloading illegal material the business might get it seriously in the pooper.
Alternatively, get the I.T Consultants to block the ports on the work firewall and job done. It will no longer work for her, and she'll either balls up and ask why its not working or stay quiet - probably the latter.