Seems a bit odd not to let in Service offspring ahead of Civil Servants
Hardly. An MoD CS who has worked in the Box with many serving RAF officers is rather more deserving than some scaley brat who perhaps hasn't had anything to do with the military for decades.
Nice though your client might be, her father left the RAF almost 40 years ago having never been a Club member, apparently. Why should that give her any priority over a current MoD CS?