The Alfie actress has been painted as a hypocrite in the British press, after it was reported earlier this month (OCT05) she struck up a romance with her Layer Cake co-star while she was still dating Jude Law.
Only days after the news broke, Miller claimed she had broken up with ex-fiance Law back in July (05), after he confessed to cheating on her with his former children's nanny DAISY WRIGHT.
Miller's mother JOSEPHINE says, "Sienna is unhappy with the hassle she is getting.
"She wants to live a more private life and she knows she will get that in America. Plus, she knows it would be very good for her career because that's where the film industry is biggest."