Sometimes siblings drift apart as they get older, but not Bindi Irwin and her younger brother Robert Irwin. The 26-year-old daughter of Terri Irwin and the late Steve Irwin is still as close as ever with her 20-year-old brother,

Bindi Irwin and husband Chandler Powell said that daughter Grace, 3, will probably be their only child in an Australia Zoo YouTube Q&A. The couple said they feel 'very lucky' to have Grace and they are 'so happy with our little family at three.

Growing up as the son of the late Steve Irwin, the world watched Robert Irwin transform from a cute little boy into a young man with a promising career of his own in animal conservationism—so it was no surprise that fans couldn't get enough of a recent throwback pic posted by the 20-year-old on social media.

The children of the late Steve Irwin are seen smiling at each other with the Wheel of Brisbane in the background. In the original picture, 10-year-old Robert is much shorter than his older sister and he is sporting a very prominent bowl cut.