B, My Name is Bunny — Norma Fox Mazer

Bunny is funny, but that doesn't mean she's totally clueless when it comes to more serious matters

With her quick wit and lighthearted personality, Bunny Larrabee can make people laugh about almost anything. She collects knock-knock jokes, riddles, and all kinds of comedy routines to try out on her best friend, Emily.
 
The only thing Bunny doesn't find humor in is her unusual name -- she's heard jokes about it her whole life, and none of them are funny. So when an impossibly gorgeous guy starts talking to her at a concert, Bunny opens her mouth and says two fateful words: “I'm Emily.”
 
It's just one tiny lie, but it will drive a wedge between the two best friends. And with what looks like more serious misfortune on the horizon, Bunny will need Emily's friendship and advice more than ever.