Irene wasn’t the easiest role to research for Rachel McAdams, who stars as the character in the updated version of Sherlock Holmes. After all, Irene wasn’t exactly a staple in the series of stories.

Still, it’s not like McAdams is disappointed. It gave her the freedom to put her own spin on Irene’s personality.

Click on the video for why Rachel McAdams was glad Irene wasn’t a well-known character in Sherlock Holmes.

Sherlock Holmes opened on December 25th with the largest box office take in the history of Christmas day debuts, grabbing $24.9 million.