Two littles and one big

I very last minute added another chick to my order from a breeder, and ended up with two littles and a monster. 🤣 Right now the littles are acting like the frizzle is their mother, and she is actively stepping up to the role despite her young age. They hide under her, and she shows them where the food and the water is. Is there anything I should be worried about as they continue to grow? I don't really want to separate them even though she will be ready to go outside well before them.