Amy Robach has had reason to celebrate over the past few days – with Mother's Day, positive test results, and most recently, her daughter Annie's 15th birthday.SEE: Inside GMA stars incredible homes - Amy Robach, Robin Roberts and moreThe Good Morning America star took to Instagram on Monday to share a series of never-before-seen pictures of the birthday girl from over the years, which went down a treat with her fans.Photos included one of Annie as a little girl with a vast collection of