The 64-year-old actress would star alongside Julia Roberts, Ewan Mcgregor and Benedict Cumberbatch in the star-studded comedy drama scheduled for release next year, reported Daily Express.
"(How did I prepare?) it was a lot of smoking and bad posture and staying up late drinking red wine with (actress) Margo (Martindale)," Streep said.
The story follows the lives of the strong-willed women in the Weston family, whose paths have diverged until a family crisis brings them back to the Oklahoma house they grew up in, and to their dysfunctional matriarch.