Is Sally Field the best choice for portraying crazy women?

Is Sally getting typecast?

"The recent best actress Emmy winner (ABC's 'Brothers & Sisters) is attached to play Mary Todd Lincoln in Steven Spielberg's long-gestating biopic 'Lincoln.'

I think she will make a great "crazy" first lady. First she was the crazy "flying nun" then "Sybil" then she played the crazy run-away-bride in the "Smokey and Bandit" classic films.
She then went on to television to play the crazy mother of Dr. Abby Lockhart on "E.R." (Abby played by the super foxy Maura Tierney, pictured). I'm sure she has played other crazy people - I just don't have the time or desire to look Sally's profile up on IMDB.