I have heard the mom thing but I view them all as parts of a mom. Yes, even Amethyst that might be more like a sister

Pearl being organized, cleaning and deep caring that has to stay behind strict so that Steven learns lessons.

Garnet being the protective side, the side that may yell but knows when to apologize, the sturdy shoulder, the one to give advice.

Amethyst being the fun and happy, knowing the darkness but moving past it, not afraid of showing Steven he can be strong too, trusting that he can handle thing she throws at him or trusting he can do things for himself, showing him it is okay for him to be a kid.