Audrey Hepburn has been a lasting source of inspiration. From style goals to interior design goals to beauty goals , she has always remained supreme.Now, we are getting an even closer look at the Hollywood icon's private life and personal musings. Bonhams , a privately owned British auction house, recently revealed that it will auction off a collection of never-before-seen letters that had been in the possession of the late actress In the letters, spanning a nine-year period from 1951 to 1960, Hepburn writes about her children, her travels, and her relationships. One such relationship was with American actor Mel Ferrer. The two would marry and have a son together, Sean Hepburn Ferrer, but later divorce in 1968.One of the 10 recently unearthed letters may just prove the old adage that "mother knows best." Hepburn's mother, Ella van Heemstra, wrote to her daughter in 1961 that Ferrer was a "frog faced delinquent with the spindly legs." In another, she criticizes him again, writing, "I believe that Audrey is getting rather sick of the neurotic side to him!"Van Heemstra also said the actor had caused "sufficient havoc to last a long time." In hindsight, the divorce doesn't seem so shocking. Ferrer would go on to wed a total of five times over the course of his life.If you have a couple thousand bucks to spare, the letters will go up for auction June 29 as part of the Bonhams' Entertainment Memorabilia sale — personalized motherly advice is not included.