All these things are case sensitive , so putting in the exact copy of what is printed underneath is imperative .
Make sure that what she is copying down is the actual security key , there maybe other numbers/letters there as well .
If all else fails you/she could always access the router set up pages and change the security , whether it be WEP or WPA to something else and try again . The address for accessing the set up is 192.168.1.1 , type this into an address bar in a browser and press enter , both user name and password for access is admin . Look for the Wireless tab , then encryption , you can change things from there .
Jusy had a look at the router PDF , the security key is usually ( if provided by Tiscali , this is one of their preferred routers ) in WPA code , as said above this is case sensitive so it must be copied accurately . It does sound like she isn't putting in the same code in the bottom box as she is in the top one .