Tim McGraw may be a country superstar, but he showed that he's also a proud papa bear on Thursday. As Taste of Country reports, the singer celebrated his youngest daughter's birthday by sharing a sweet post on Instagram. The post included multiple photos of 17-year-old Audrey, from when she was a tiny baby snuggling with him to present day. He wrote, "17 years ago this precious little jewel came almost 8 weeks early to us! So tiny, but so strong! Her mom, her sisters and I love her endlessly. She is our baby girl and she has grown into an incredibly smart, beautiful and powerful young woman who will be a light in the world!! Happy birthday Audrey Caroline McGraw...you are loved beyond measure."