Every trio Luffy is in involves 2 CoC users and one CoCless.
Luffy, Zoro, and Sanji
Luffy, Ace, and Sabo
Luffy, Kid, and Law
So regarding Luffy’s family. Statements made in marineford seem to indicate Dragon had CoC. Therefore via the law of trios, Garp won’t have CoC.
the family trio:
Luffy, Dragon, and Garp