This list is about books that I read in 2013 that were published this year. I'm going to name sibling relationships that I liked in books, and I will give a brief explanation of why that sibling relationship stood out to me.
Carey and Jenessa in If You Find Me - Carey is pretty much all that Jenessa has at the beginning of the book. She is really more like a mother to her young sister. When they first start living with Carey's father, Carey feels protective of Jenessa. She doesn't want to let other people get close to her sister. This is understandable, and it shows how much she really cares.
Lucky and Cole in The Culling - This sibling relationship isn't shown as much through actual scenes with the characters. This is more about how much Lucky loves Cole and wants to protect him in the dystopian world that they live in. His love for Cole is clear whenever he thinks of him.
Gray and Blaine in Taken - This relationship is interesting because Gray and Blaine are quite opposite, so they don't always get along, but there is a secret about them that they don't know. When they find out this secret, it changes things in their lives.
Imogen and Hunter in Bruised - This relationship is quite strained, but I felt like it was portrayed well. Imogen has been mad at Hunter because he slept with her best friend, and it makes sense that that would make her mad. There are some good conversations between them during the book, though.
Meg and Teeny in The Rules for Disappearing - Being in Witness Protection is hard for Teeny because she's so young, and she isn't even able to be herself. She is always stuck pretending to be someone else. Meg is always there for Teeny to protect her and comfort.
Fia and Annie in Mind Games - This is probably one of my favorite book sister relationships. The book is told from the perspective of both girls, and it is clear that each one loves and cares for the other very much.
Amy and Baby in In the After - Amy and Baby are not really sisters, but their relationship is like a sibling relationship. They are all each other have in the post-apocalyptic world, so it is like they really are family. They love each other, and they have their own secret language that they can communicate in.
Wick and Lily in Find Me - Wick clearly cares about her younger sister. Lily doesn't approve of what Wick is doing, and she wants to have a good life, with parents who care about her. Seeing how much Wick wants to protect her is really sweet, even if her methods of protection (hacking to solve mysteries) are illegal.