Harry Potter and the Prisoner of Azkaban
by J.K. Rowling
House: Gryffindor, 2nd Year
Ginny isn't around much at all in this novel, and given her prominent role in Book 2, this lack is a bit noticeable. However, how many of you hang out with your younger siblings at school? Are those crickets we hear? Yeah, we thought so.
Ginny is a year younger than Harry, Ron, and Hermione, so it makes sense that she'd be off doing her own thing and making her own friends this year. We do see her briefly over the summer, though she gets a bit lost in the crowd with the other Weasleys. Oh, and she still has a bit of a crush on Harry.
Ginny Weasley, blushing furiously, turned up with a get-well card she had made herself, which sang shrilly unless Harry kept it shut under his bowl of fruit. (10.1.2)
Other than that, Ginny is off doing her own thing in this book.