In this picture Dante is about six months old, and Domino is a year older than that.
At the time they were both about the same size. Domino hasn't grown at all and is a petite 6.5 lbs. while Dante has topped out at a whopping 24 lbs.
Their relative sizes really don't matter, though. Domino was the boss lady then, and she's the boss now.
And that's because Lady cats rule!