Even considering women writers writing in English only, she'd be considerably behind writers like Marilynne Robinson, Donna Tart, A.S Byatt or Arundhati Roy in the accomplishment of her work.
'Oryx and Crake' and 'Handmaids Tale' are some of the most vivid and impactful speculative fiction that I have ever read. Margaret Atwood will forever go down in history for both the prose and scope of her literature.