Thanks everyone!
Zhucca, very busy! He's a pretty active pup, but not quite as active as Keira was fortunately. He does love to play though, and is always trying to chew things he shouldn't be. He's incredibly sweet though, and loves people so it's not hard to keep him occupied. Unlike Keira, who couldn't care less about anyone but herself at his age, haha. Dance is good at playing with him too, which is nice. Keira doesn't know how to play with him yet, but likes him, and Spring is just ridiculous. She ran him over like she didn't even realize he was there earlier, and then pounced on him a little later on. So she's not allowed to spend much time with him.
Southpaw, Dance is 18" tall and 32lbs, so not very big. Ripley was roughly 15" when I measured him earlier, and he's 20lbs. So there's certainly not too much of a size difference between them!