There is a lot of rudeness of Ellie towards her mother. She names her Marion instead of mom because her mother refuses to call her Ellie instead of Elisha. As long as her mother calls her Elisha, she will call her Marion.
It is also rude to judge about the relationship of her parents or even to talk about it. This should not be of her business. It is the same with having doubt of the love of her parents. In chapter 15 Ellie asks her sister if they ever loved each other.
In fact her mother once left the family but she came back. This should be done and over and not mentioned through the rest of her life. Elli uses it against her for example in chapter 18. In a conversation with her mother she says: “What do you deserve, Marion? You went away-just left-boom-out of here.” Later she tells her: “Believe it or not, everything isn’t about you”. Ellie seems to be a fickle teenager.
On page 103 Elisha tells Jeremiah that her parents named her after a city they have travelled to. However there is no Sidney in Australia. Woodson probably meant Sydney (which is in Australia). Why did Woodson spell it like this? Is it a typing mistake or did she do it on purpose?