The 18-year-old actress, who stars in the Twilight films and also worked with Kristen in Joan Jett biopic The Runaways, talked to Instyle magazine about the scandal surrounding Kristen after it was revealed she had cheated on Robert Pattinson with Snow White And The Huntsman director Rupert Sanders.
Dakota said: "Everyone thinks they have the right to, you know, publicise the struggles and sadness and heartbreak and all of that. It's like, 'Why do you think you are the authority to judge people's experiences?'."
Meanwhile Kristen and Robert both appeared on different talk shows in the US to promote the final Twilight film, Breaking Dawn - Part 2.
K-Stew, 22, told Jay Leno how the shock ending to the film made her "giddy" while R-Patz, 26, joked with Jimmy Kimmel about a picture that emerged of him drilling his name into a table in a New York bar.
Both avoided talking about their relationship.