The actress was embroiled in a cheating scandal with the married director last year, due to which her relationship with Robert Pattinson suffered a setback.
Now, after their second breakup, the Twilight Saga star has renewed links with Sanders, reported Heat magazine.
"Kristen was feeling low - the lowest she's ever felt - when Rob flew to Australia... so when he left, she reached out to Rupert to see if he was okay and suggested meeting for a coffee," said a source.
It is thought that Stewart contacted Sanders two weeks ago in order to "talk to someone who was going through the same thing" after it emerged that his wife Liberty Ross had filed for divorce.
However, Sanders is thought to have declined Stewart's offer to meet-up, with Robert Pattinson apparently finding out about her plans through a mutual friend.