Gracie is Tim and Faith's oldest daughter, she is only 19 years old. They have three girls together, Maggie is 17 and Audrey is 13.
While on stage, Gracie was dressed in a summery top and form-fitting high-waisted jeans. She joined her famous father to sing "Here Tonight," a new song from his upcoming album. Videos from their duet later surfaced on YouTube, and showed the pair expertly harmonizing together. #CutestThingEver
She wasn't the only family member to join Tim on stage that day, either. There are reports that his wife Faith also sang with him, and they performed their legendary love song "It's Your Love".
This isn't the first time Tim's let everyone see his family. They showed up with him to the TIME 100 Gala in New York City earlier this year.
Watch Tim and his all-grown-up daughter sing, below. She's gorgeous and talented just like her parents!