Ahh okay, I can see that. It's actually in first person, from Miri's perspective, but there isn't a chance for "I" yet because she's describing what Leah is saying and doing here at the beginning. Alternating chapters are from Leah's perspective in the submarine.

I don't have my copy next to me, but I think the first line is italicized and it's supposed to be something Leah just said.... I think "unstill" is also italicized to show that it's the word Leah says.