How does the book end? Does her Savvy save her dad?I feel if I know about the story, I can help my student as it will be familiar to her as she...

Mibs' savvy is that ink on skin--tattoos, fake tattos, a smiley face drawn with pen on a hand--can speak to her.  At the beginning of the novel, it is mentioned that her father has a tattoo of a mermaid on his arm.  At the end of the book, Mibs makes it to the hospital, and although she does not "save" her father, she is finally able to hear the faint song of the mermaid and know that her father is coming back to them.