MAC with Virtual windows 7
See if this will work. If everyone is on the same network and network group name you should be able to see the printer.
I am assuming he/she is printing from the Mac side to a Windows printer that is shared. I think it should also work form his virtual Win7 side as it should see the other Windows machine on the network.
I have a mixed network in our religious ed office but the printer has its own ethernet port so that an iMac and WinXP can still access it.
Use the hint above as guidance.