Call up Linksys yourself or ask your grandma to call them.. Here is a list of their telephone numbers, choose them according to your country. http://support.linksys.com/en-apac/contactus
If you prefer not to call the linksys support, then what you can do is ask her to go to a page like routerlogin.net(This one is for netgear products) so you can find a similar one for linksys by googling that up because there might be a case that the IP is not 192.168.1.1 it is something like 10.0.0.1, otherwise what you can do is go to run and type ncpa.cpl and then check the lan connections, if it shows connected then right click it and go to status and check the default gateway and then type that address into the web browser.
If in ncpa.cpl it does not show connected, and shows disconnected then the cable is not plugged in; otherwise if it shows disabled then right click it and enable it; but if it shows limited then also go to status and do the same.
This is all what you can try but if everything fails, just call up linksys and ask for help.
If now you are satisfied with the answer kindly put a tick on the left hand side. Hope i helped you :D