Adelia Zeidler and the Ocean's Eleven star have remained close throughout Clooney's rise to fame and over the years the siblings have kept in touch via email because it is the safest way for them to communicate.
She tells the New York Daily News, ""I just generally keep him up with what's going on in my life. I don't generally ask him what's going on in his life because I don't want to accidentally say something (to the media) that I shouldn't.
""He'll tell me things that are going on here and there but mostly we gab like brothers and sisters do about inconsequential matters.
""I do not have his phone number because I wouldn't want to have it in my phone and then lose my phone. He can phone me and he does occasionally, but the email is more convenient for both of us.""