Sibling Rivalry

So, earlier this week, I came to an epiphany about the story Ellen and I wrote. I called her up last night to talk about it. Considering we wrote the story, it seems like this would have been obvious.
Arith and Saleera's story is entirely about sibling rivalry.
Now, the first part of it was intended. Both Arith and Saleera have older brothers that indirectly drive them to their quest.
But even after that, EVERYTHINg is fueled by sibling rivalry.
You got Nex and his adopted brother, and then you got the problems among the princess twins.
Everything comes from sibling rivalry. Arith and Saleera's journey, Ginger's flight, Nex's banishment, and the destruction of the towns. Especially the finale. I didn't realize that that was such a huge theme until a few days ago... Even though we spent a few years writing and editing it...
It's like that author speech I went to - that Chabon guy. As he was talking to us, he said that his story was about escape and that he didn't realize it until that moment. Unintentional themes introduced into the story... How strange that such stuff pops up without the author noticing.
And then there's what John Green said in that video I posted about book analysis. That it doesn't matter if an author intended something "deep" in their book. The fact that it's there makes it important.
Here's the funny part. I DID do the thing where Arith is always overshadowed by his brother, Bram. That's what made him leave home in search of a dragon. But the other three HUGE sibling rivalries were created by Ellen. Not to mention that Nex and Jade's sibling situations are very similar.
My goodness, Ellen, is Kelly really giving you that much trouble?
^-^'
So, Ellen, what have you to say on the subject of sibling rivalry? I have no siblings. Unless you count Alaska and Lanayru (Rabbit and snake - and my fish too, I suppose)