In this adventure, Nikki Maxwell has to deal with a bratty younger sister.

Lately, Nikki’s little sister has been a TOTAL BRAT! But while Brianna is busy raiding her closet and taping a HIDEOUS drawing of Nikki on her bedroom door, Nikki has more important things to think out. It’s the end of summer and she has only 72 hours to completely reinvent herself before starting at Westchester Prep. Nikki is determined to be the COOLEST, CUTEST, SMARTEST, MOST INTRIGUING girl at school. But when disaster strikes and Brianna gets hold of Nikki’s most cherished items. her phone AND her diary, her world is turned upside down. Will an unexpected emergency ruin Nikki’s fabulous start to the new school year or, worse, ruin her relationship with wacky BFFs, Chloe and Zoey, and cute crush Brandon?