There's a bit of missing information with your question. Is she using a smartphone, computer, Mac, or Windows?
For starters, you need to secure the device, and any network shared files, folders and drives.
Say it's a windows platform, the first step is to password protect all network shared drives. Or alternatively turn off all file sharing and network discovery. Under control panel, network and internet, network and sharing center, advanced sharing center, is where you can turn it all off and back on. An extra step would be to encrypt drives and folders, but might require additional software. Mac also has a an easy to use encryption utility tool.
Next thing to be very aware of, is that ALL the web traffic, meaning stuff going and coming from the online internet connection can be intercepted and sniffed by attackers in the building. So how does one efficiently protect his online data on any public wi-fi network?
A VPN is the answer, invest into something like privateinternetaccess, they have very cheap yearly plans. VPN services like this one pretty much encrypts all the web data, making it very difficult, impossible when well configured, for any external parties to snoop on the Wi-Fi traffic.
The VPN might slow down the connection speed for her a little bit, but it's well worth it. Say you're in New York, connecting to a server in California might cause some delay, using one in New York however will have little impact on speed. So distance matters. If all you're after is securing the data on this public wifi, using a local VPN server will do the job, so consider that when choosing a service provider.