Well the way I figure it, their building is hooked up with ethernet and a central server located somewhere within that buildling. Similar New Brunswick and parts of B.C where they are experimenting with Fiber-to-the-Home. Yay, Canada decades behind the U.S. hah. oh well.
So each person in that building is sharing the one connection, whatever it may be. Sure, lan is 100/100 but the actual connection could be something like 50Mbit/5Mbit. So one or more people are torrenting like mad, which the landlord/caretaker is probably participating in. Why wouldn't he? I sure would.
So there really isn't much that can be done other than to bring it up with the buildings caretaker/landlord and perhaps that landlord, if there isn't some sort of decent server/firewall, should be looking into a solution that would involve shaping the traffic or at least distributing the traffic accordingly. If Nina. is getting a public IP address then I am guessing that the building has an alotted amount of IP's purchased through the ISP for each tenant or a modem for each apartment in a central location easily manageable.
It definatly would be something to look into. We could suggest everything in the world to help Nina, but if what I stated IS infact the case, then our efforts will be in vain. Certainly, however, she should stick with using the router as I am sure there is no protection offered in the building.