Great question!
The older ones are Girl-Girls and Roo. Roo is such a character that his name changes often. He has been Mr. Roo, Rudy Roo, and Rotten Roo.
My 4 SLWs are hard to tell apart, so they don't really have names. One of them was Big Mama, but now the others are the same size, and seem to have the same rank.
Red mixes: I had 3 that were easy to tell apart by coloring and personality. There are Red Momma, who for a while liked to sit on her eggs; Red Meanie, who always plays the bully; and Red Sweetie, who was the only one who liked being picked up, but she is the one I lost.
The 3 blue copper marans have not named themselves yet. I don't know what their personalities are, and they still look pretty much the same.
As for the 5 babies that I call Peepers: so far the only ones with names are Blondie, an RIR with a yellow head; and Brave One, who always comes to check me out while I am changing food and water.