What do you think packet sniffing is? It’s not what a dog does when he smells your bum but I guess you could call that packet sniffing too. I am taking about a software program that runs on a computer with a network card that can run in a promiscuous mode (hooker mode).
This slutty software sees everything and does nothing. All the data pouring across the line just logging traffic. You can tell her what to look for as far as packets and protocols goes, then go back later and analyze the data.
Great tools for finding problems on networks, viruses, getting passwords and personal data over a network etc.
One good one to look for is WireShark you can load it up and start sniffing some packets yourself.