Reese Witherspoon's fans had to do a double take after the Big Little Lies star shared a photo of her daughter Ava on Instagram over the weekend.The Legally Blonde actress posted a sweet picture of her firstborn sitting outside in their beautiful garden with her little brother Tennessee, and at first glance, Ava could have been mistaken for her famous mum.MORE: Reese Witherspoon's blue-themed home will leave you speechless VIDEO: Everything you need to know about Reese WitherspoonFans were quick