Tim McGraw and Faith Hill's three daughters have all come of age, but that doesn't mean that a proud daddy can't get a bit sentimental on his baby's birthday. McGraw posted a sweet tribute to his youngest daughter, Audrey, who turned 19 on Sunday (Dec. 6), telling the world how special the last child — who is getting ready to fly the coop — is.

"This lil punkin has been a full on million watt light in our lives since she arrived on this day," he captioned a series of photos of Audrey. "You are so loved by everyone who knows you, but I want you to realize how deeply your mom, sisters and I love and adore you."

He continued, describing her as "a steadfast friend" who is "dedicated to what you believe and always willing to listen and learn."

McGraw summed it up by noting: "I admire you."

Meanwhile, mom Hill did her own share of marveling how the youngest kid in their clan has grown up. She posted a video of Audrey — apparently suffering a broken ankle — acting out "Dear Prudence" from the 2007 movie Across the Universe. As Mom noted, this was Audrey's "true passion."

"Audrey was born almost 8 weeks early but we all knew from the moment she arrived that she was ready to conquer the world," Hill wrote. "Her sisters gave her so much love and protection that she knew she would have wings to fly to any dream that she could imagine."

McGraw, who canceled his 2020 Here on Earth Tour earlier this year due to the ongoing pandemic, said that he's been using this year to do a little road tripping with Hill and their youngest kiddo, reportedly packing into the family’s 15-year-old Cadillac Escalade to go visit Audrey's older sisters, Gracie and Maggie, who currently live in California.

As for Audrey's future plans, "She's about to leave the house. She's been stuck with us her senior year," McGraw says. "She graduated this year from high school. So her senior year, all the way from March when the world, sort of, changed, she's been stuck with us pretty much solid the whole time."

There's no word yet on where the youngest McGraw will fly off to, but McGraw and Hill recognize the fact that they were able to have uninterrupted time with her during the pandemic as an unexpected "blessing."

See Tim McGraw and Faith Hill's Best Pictures Together Through the Years

Tim and Faith's Most Unforgettable Moments