Riley Keough wrote an emotional letter to her grandmother, Priscilla Presley, detailing how hurt she was about being taken to court after her mother Lisa Marie Presley died. The letter, obtained by Us Weekly on Friday, September 5, was made public in an amended lawsuit submitted in Los Angeles Superior Court earlier this week amid Priscilla's legal battle with former business partners, Brigitte Kruse and Kevin Fialko. According to the letter submitted in the filing, Keough wrote about feeling heartbroken that her grandmother attempted to take her to court after her mother's death.