for Honestly, Mallory! by Laurie B. Friedman and Barbara Pollak
From the Publisher
Everyone seems to know what they want to be for Career Day at school'that is, everyone except Mallory. She can't seem to find anything she's good at. When she finally decides to be a fashion designer, some of her classmates laugh at her. And then, before she can stop it, out pops a lie?Mallory tells everyone that she's won the Fashion Fran fashion design contest. Mallory's lie grows and grows until she must face the truth and make amends with her class, friends, teachers, and parents.
Publisher description retrieved from Google Books.