Does she have iCloud and Find My iPhone enabled? If so, and she remembers her iCloud password, then you need to do the following:
1. Do an
iCloud backup.
2.
Remote Wipe using Find My iPhone
3. Reactivate the phone and restore from the iCloud backup.
If she doesn't have iCloud, or doesn't remember her iCloud password, then you're out of luck until you can get to a computer. Then you can do the following:
1. Back up her data through iTunes.
2. Restore the phone from iTunes.
3. Restore using the backup you made, just before the wipe.
Full instructions can be found here:
http://support.apple.com/kb/ht1212