She is yet to react to the scandal after her director husband issued an apology admitting he had cheated on her, and her last tweet was a simple "wow", written moments after a magazine called Sanders' representative for comment.
The 33-year-old model and mother-of-two, who played a young Stewart's mother in "Snow White and the Huntsman", also retweeted a Marilyn Monroe quote: "Sometimes good things fall apart so better things can fall together."
She later followed this with another retweet, this time quoting American author and poet Maya Angelou, saying: "If you find it in your heart to care for somebody else, you will have succeeded."
"Wow," was her final note before signing off.