Nicole Kidman and her sister, Antonia, are incredibly close - and they look alike too!The Australian star's younger sibling shared a sweet family photo on Instagram with her son, and it's clear the Kidman gene is a powerful one.MORE: Nicole Kidman discusses major change impacting her familyIn the photo, Nicole's nephew, James, was wearing a suit and tie and being hugged by his mother who was celebrating him heading off to his prom. WATCH: The Prom is set to be a Netflix Christmas hit!Her