Policy
As far as I know, the only family that gets to fly for free on the federal dime even to official functions is the family of the president. Congress and cabinet member families have to pay. Staffer families have to pay. I don't know what the policies of Alaska are, but in every state I have lived in, family doesn't get to fly off on vacation for free- and even if the accompany on business, I suspect its asumed that they have to pay.