The movie earned US $129 million at the box office and has become an instant comedy classic.
Lohan is so keen to return to that world, she has even begun writing the sequel herself.
"I have already written a treatment for it. I just need a response. I know Mark Waters, the director; he'd happily come back."
The script was written by Tina Fey and based on the book Queen Bees and Wannabes.
McAdams has previously said she would return to the role if Fey, who co-starred in the movie, wrote the sequel.
Lohan's career has dipped in recent years after issues with drugs and alcohol. She will next be seen in The Shadows Within.
She may be dismayed to know that ABC Family has already made a Mean Girls 2 back in 2011, but to that we can only say: