Hey please do not panic. Sometimes handsets can take a bit of fiddling around until it works
Go to Settings > Wireless and networks > Mobile Networks > Access Point Names > Menu Key > New APN then enter the following:
MMS proxy: 220.127.116.11
MMS port: 8080
Authentication type: PAP
APN type: default,supl,mms
Enable/disable APN: tick box (APN enabled)
Press menu and save the apn then restart your handset.
If you cannot get it to work, try contacting an agent but please give them time to respond, they're very busy x
These are the settings I have on my S3, covering both ICS and Jelly Bean. If her phone has either of these she should be fine.
Open Settings then click MORE SETTINGS
Then click MOBILE NETWORKS
Next click ACCESS POINT NAMES
From here press you menu key which is the touch button to the left of the home button
Next select + NEW APN from here enter this information
Name - giffgaff
APN - giffgaff.com
Proxy - 18.104.22.168
Port - 8080
Username - giffgaff
Password - password
MMS proxy - 22.214.171.124
MMS port - 8080
MCC - 234
MNC - 10
Authentication type - PAP
APN type - default,supl,mms
Enable/disable APN - tick box (APN enabled)
Bearer - unspecified
After this press you menu button again and select save.
This will take you back to the select APN screen, from here select your newly created giffgaff APN by clicking the small circle next to the giffgaff APN this will make the circle go green
next press your back button and ensure you USE PACKET DATA box is ticked (this does not appear with Jelly Bean)
Then go back to the main settings page and Set Wi-Fi to OFF Return to home screen. Reboot your phone (turn off and on again).