Warren Beatty's teenage daughter with Annette Bening wants to undergo sex change surgery to become a male, according to a U.S. tabloid report. The National Enquirer claims 18-year-old Kathlyn Elizabeth Beatty, the Hollywood couple's eldest child, has adopted the name Stephen Ira and has been dressing and living as a male for some time. The teen, who is now legally allowed to make her own medical decisions, is said to have been researching the gender reassignment operation - the same surgery Cher's daughter Chastity underwent earlier this year (10) to become Chaz Bono - with a view to having the procedure done in the coming months. A source tells the tabloid,