I was thinking, she can't really be considered a socialite anymore, can she? I mean, she is pretty much never at the typical 'Society' events these days (ballet, opera, the charities that we associate with the Ladies Who Lunch...); I guess you would say she is a fashion celebrity now? 
I found Olivia's Sweater Coat. It is by Pringle of Scotland and it is called the zig-zag Sweater Coat. It costs a whopping £1569.
oliviapalermo.com and mytheresa.com