Somtree,
Go to the National Archives of Australia website and open the Namesearch address.
Enter family name Ford - there are 424 Fords.
Refine with George - there ar 47 possiblilities of first or second name George.
The page will show name, POB (place of birth) and NOK (next of kin).
Trawl through these three pages and you will find a number approx. 5 or so that have given their place of birth as England. You can open their service records and check to see if it there is any further info that might suggest it is your GF.
Just remembered that many chose to enlist under other names and aliases, so don't be put off by a first scroll through.
I don't know Sngland well enough to know if Bromley, Lingfield, Shapwick or other such names are within cooee of London.
Good hunting.
Regards,
Geoff