Gwyneth Paltrow has left fans confused after sharing her daughter Apple's unexpected interest in a birthday post.The 51-year-old Academy Award-winning actress took to her Instagram to wish her eldest child a happy birthday.Paltrow shares the 20-year-old and her 18-year-old son Moses with Coldplay frontman Chris Martin.The former A-list couple tied the knot in a secret Santa Barbara wedding in December 2003. They eventually split in 2014, finalizing their divorce in 2015.