@desa:
The incident Law his taken revenge for happened 13 years ago. But last time Dofla and Law were in contact was 10 years ago.
It's already been said, but, yeah, Law would've known about both Monet AND Sugar if he stayed with Dofla until 10 years ago, since we now just learnt that Sugar (apparently?) got her powers 12 years ago. . .
. . .unless ONLY Dofla and Law met 10 years ago and not any of his crewmates.
Be that as it may, for the timeline to work (Law at least not knowing who Sugar is and what's her DF power), Law definitely should've left Doffy 13 years ago and, then, going by that estimate, yes, Dellinger was 3 years tops when he joined Doffy's crew.