I think Rex and Rose must bother be the image of Stacey when she was younger. That's why her Narcissistic self favours them so much.
Poor Rex, he really has been tossed to the side. Rose's hair looks awful, just like Rex's used to. She's desperately layering the curling products in it and it probably putting rollers in like she did with Rex too.
I have a curly haired baby, you do not need to put that much product and work into getting their hair curly if they are really curly. You just don't.