Look, we're going to be honest—Summer isn't the most happy-go-lucky of narrators. She's not the kind of twelve-year-old who's going to tell you about her My Little Pony collection or her latest crush. Instead, she's the kind of girl who's constantly anxious and on edge. She says things like:
I turned and walked away. I felt lost. I might as well have been spinning in a round metal tub, in a twenty-foot wall of water, washing down off the mountain. Just lost forever in Deep Water. (5.37)
As she tells the story, we get the sense that she's always looking over her shoulder, always worried that Uncle Ob will drop dead and that she'll be left in this world all alone. As we read, we get the sense that Summer wants things to work out, but that she's scared and worried that they won't. She just wants to see Uncle Ob get better, and is frightened whenever he seems to be descending into depression.