Mick Jagger has backed out of penning his own autobiography a few times, but a former girlfriend is putting some of his writings on the auction block. Marsha Hunt, the inspiration for the Stones hit "Brown Sugar" and the mother of Jagger's oldest child, daughter Karis Jagger Hunt, has signed on with Sotheby's in London to sell letters that Jagger wrote to her between July and August 1969, while he was filming "Ned Kelly" in Australia. The set is expected to snag between $111,000-$160,000. Hunt told The Guardian in Britain that, "I'm broke...I had friends who came to visit from Pennsylvania and there was no electricity in the house because the bill had been too high...One friend said, 'Surely you have something you can sell?'." She considers the letters to be "important. The letters speak for Mick at an incredible juncture in our lives. The summer of 69 was the end of a whole era of revolutionary spirit -- we didn't know it was about to die...The sale is important. Someone I hope will buy those letters as our generation is dying and with us will go the reality of who we were and what life was...Someone will protect them (the letters) and someone who protects them will protect me because I will make enough money from the sale to repair my house in France." Jagger's relationship with Hunt and their daughter was kept largely secret until 1978, when Hunt sued Jagger for child support during the "Some Girls" tour.