Psychology A-Level, schemas

Hey, so, I'm catching up on lockdown stuff and I was wondering if there can be schemas inside of schemas. So, like, if there is a big schema, e.g. children thinking that 4 legged animals are dogs but only seeing small dogs than they see a bigger dog, will that size thing go into another schema inside 4 legs=dog schema but be a small and big dogs exist schema in that? Sorry if that doesn't make much sense, I'm confusing...

I'm sorry but that just went straight over my head.

I am by no means an expert but I'm pretty sure "sub-schemas" aren't a thing - they just grow. So, using your example, the child might first see some small dogs and form the schema "4 legged animals". Then when they see a large dog, this schema adapts to include the new size. Then they might see a cat, and add that to the schema.
When the child learns to understand language, they will be taught the different names of these animals, and the schema will split into a separate one for each animal.