In 2001, Brereton created the concept for and launched mary-kateandashley, the Olsen twins' tween lifestyle magazine, which had a circulation of 1 million.

In addition to teaching writing courses at and Columbia College, Brereton has written five nonfiction books and created marketing materials for professional associations and companies such as the Cartoon Network, McDonald's, Baker Tilly, Wolters Kluwer and Nielsen.



She has also written articles that have appeared in SPIN magazine, the Chicago Tribune, Discovery, Green Building & Design, Wealth,, Profile, Life & Style Weekly and dozens of other publications.



Since receiving a Bachelor of Science in Journalism from Northwestern University's Medill School of Journalism more than 25 years ago, she has produced magazines for Northern Trust, KeyBank, American Music Group and other clients — and edited a number of books, articles and other items for CBS, Johns Hopkins University, the National Council of Teachers of Mathematics, Kaplan and MARS Wrigley. 




She previously was employed as a senior editor at a women's magazine, an associate publisher at a custom publishing company, overseeing its financial sector publications — and was the the marketing and communications director at a legal industry association.