In the Australian National Archives (which are excellently indexed by the way, with many documents available online) I did a couple of searches on brothers Lionel and Donald FORD. Lionel is listed as Gloria Averil May FORD (his daughter)’s Next of Kin on her service record for WW2 and Donald actually joins up himself at the age of 46 with wife Edith (Edie) as his NOK. I will need to look at the records myself (only the references are online sadly) but at least it gives Gloria’s date of birth.. Hurrah!