I know the rules state that the family relationship has to be demonstrated to Qantas' satisfaction but has Qantas ever challenged anyone? I'm certainly aware (no, no, not me!) of two people where one did a "family member" transfer of points to the other, who then got the first person a "family member" ticket from another airline's frequent flyer programme because QF don't have too many seats on that route. Neither person is related to the other - although if challenged they were happy to claim a homosexual relationship (no-one in officialdom ever challenges that statement - too politically incorrect)