Abby North is a twelve year old who is trying to deal with normal adolescent woes when she starts to notice her dad is not feeling very well. Amy Ackley does a great job of writing from Abby's point of view and keeping it in an age appropriate tone of voice and maturity level. 
 I wasn't expecting Sign Language to be so focused on Abby's dad's cancer, but Ackley does an excellent job progressing with Abby as she moves from discovery of the illness to dealing with what happens afterwards. It was very interesting to watch Abby move from not knowing much about the illness to having it take over parts of her life - and also quite hard to read because it was so emotional. 
 Ackley's debut novel, while focused on a topic that can be uncomfortable, is beautifully written and full of emotion. Each scene is written very realistically and could be a good read for a younger teen going through a similar situation to Abby.