Moli was in fact an incredibly thoughtful and sensitive girl. Even with many ideas swirling in her mind, she wouldn't voice them out for fear of hurting others' feelings.
Even after she learned about the lifespan differences of the Whale-man Species, that her aunt's life might soon reach its end, and that her aunt might be held captive by Blake, she kept quiet so as not to distract Fisher from focusing on the task at hand.
In reality, she felt terrible and was full of worry, but she only allowed these feelings to surface when she went to bed at night. Upon waking up, she always appeared optimistic in front of Fisher, smiling every time he turned to look at her.
Xiayat, on the other hand, seemed a bit bored. She had wanted to try reading like Moli, but found she couldn't concentrate and barely recognized a few characters, so she ended up taking out the Arrow Quiver on her back and airing out the feathers of the arrows dampened by the water.
