In the following example, the character is a five-year-old:
Saki stared at her side. Her cousin was right: she had indeed an extra digit on one hand. How come she hadn't notice it before? Maybe it'd been there all along; it's just that she hadn't payed attention to it. But her mother had never said a single word about it. Nor had her father. Was Rika the first one to discover it?
Will it sound more natural if I write it like this (making it sound more like a children her age)?
Saki looked at her side. Her cousin was right: she had one more finger in one hand. How she never noticed it before? Maybe it had been always there; it's just that she hadn't payed attention to it. But her mom and dad had never said anything about it. Was Rika the first one to see it?
Or it's unnecessary in third person narrative?
Saki first became aware of her sixth finger at age five. Her aunt had come to the house that evening, bringing Rika (Saki's favorite cousin) with her. She had come with the intention of discussing an 'upsetting problem' regarding her husband. So Rika's mother sent her daughter to join Saki, who was talking a bath at the moment. Once together the two girls started playing in the tub. They spread foam in the air, and splashed water to each other between laughter and giggles. This was the first time they bathed together, so they were very excited. But then, Rika suddenly stopped, fixing her eyes on her cousin.
"Hey," she said pointing to Saki's hand. "You have a sixth finger."
Saki stared at her side. Her cousin was right: she had an extra finger in one hand. How come she had never noticed it before? Maybe it had always been there. But her parents had never said a word about it, nor her friends. Was Rika the first one to notice?
"You didn't see it before?" Saki asked.
Rika shook her head. "No that I remember."