ePrint, and how it really works
Printing to a printer that is capable of ePrint requires an internet connection.
Although it would seem logical that the iPad and Printer would communicate over the home Wi-Fi network, they do not.
The ePrint printer has it's own IP address and MUST be connected to the internet. It must also be registered at the manufactures website.
In the ePrint scenario, the iPad emails an attachment (the thing you want to print) over the internet to Canon/HP/Epson.
From there, the attachment is directed to the Internet IP address of the ePrint printer. Printer "usually" starts shortly thereafter. glb613 and the Apple people are correct, it all needs an Internet connection.
All is not lost however, with the aid of a printer that is AIRPRINT capable, she should be able to print directly to the printer from the iPad without the need for an internet connection.
That said, she must have a wireless network so that both the printer and the iPad can connect to it and this can be accomplished with the aid of a cheap wireless router, as mentioned in an earlier post.