She's the author of the books in the new My Tween Lifestyle Collection.
There are four books in the series: My Self, My Life, My Look and My Beauty.
The books are loaded with quizzes, diary pages and great advice! And they're all about finding your style, loving who you are and being confident.
Email your questions about fashion, makeup, exercise, self confidence, popularity... (whatever!) to our email address: firstname.lastname@example.org and we might select your question to be answered by Marlene herself!
The giveaway period has ended, but you can continue to email your questions or leave them as a comment!! The My Tween Lifestyle Collection comes out August 25th from Simon & Schuster.