A native of New York City, Willig discovered romance novels when she was only six years old, while she was attempting to find books about her idol, Eleanor of Acquitaine. Her father gave her her first romance novel..

Willig attended Yale University, where she majored in Renaissance Studies and Political Science, then studied graduate level early modern European history at Harvard University before entering and graduating from Harvard Law School. Willig briefly worked for Cravath, Swaine & Moore, a law firm in New York, while authoring her "Pink Carnation" series of books, until she gave up law in order to focus full time on the series.

What makes the books unique is that the historical romance novel structure of each novel is framed by a modern chick lit-style story--following Eloise Kelly, an American grad student, as she attempts to write her dissertation and uncover the identity of the Pink Carnation (the leader of the ring of spies and Willig's Pimpernel). Along the way, Eloise finds love with an attractive Englishman (descended from a family of spies), Colin. The books also feature several different romantic adventures detailing the exploits of the fictional Purple Gentian, the Pink Carnation, the Black Tulip, and a host of other characters from early 19th century England and France.

Lauren's books have been named a Romantic Times Top Pick! and Lauren has been nominated for a Quill Award in 2006.

In Spring of 2010, Willig taught Reading the Historical Romance at her alma mater, Yale University, along with fellow alumna and romance novelist Andrea DaRif, penname: Cara Elliott. The course received a great deal of attention for helping to bring the romance novel academic notice.