Powell was born in Florida and married the Australian wildlife conservationist in March 2020.
Bindi introduced Grace to some baby kangaroos. Photo / Instagram
He also documented Grace meeting some baby kangaroos at the zoo.
"Introducing our @australiazoo kangaroo joey to our human joey. Grace absolutely loved meeting the littlest roos with her mama," the proud dad wrote alongside the snapshot.
In June, Bindi put her grandfather Bob Irwin on blast after leaving him out of a Father's Day post about "the three most incredible fathers in my life".
When asked by a fan on Facebook why she hadn't included her grandfather – who is her late dad Steve's father – Bindi claimed he had caused her "enormous pain".
In the wake of the subsequent media storm, Bindi announced she would be "taking a break" from social media in the interest of preserving her mental health.