Robert Irwin Says Sister Bindi Is Prioritizing Motherhood After Announcing Social Media Hiatus (Exclusive)

Robert Irwin can't say enough great things about his older sister, Bindi, becoming a mother.

Robert Irwin can't say enough great things about his older sister, Bindi Irwin, becoming a mother. ET's Rachel Smith spoke to him about his upcoming Shark Week special, and he also gave an update on Bindi after she announced earlier this month that she's taking a social media break.

Bindi and her husband, Chandler Powell, welcomed their now 3-month-old daughter, Grace, back in March. Last Monday, 22-year-old Bindi announced on her Instagram that she's taking a break from both social media and public events to focus on her family. Robert told ET that Bindi is definitely prioritizing motherhood.

"She's just the most kind, just genuine person that you'll ever meet and now to see her as a mom, it's just amazing," Robert tells ET. "She is such a good mom and she's really tried to now prioritize just time with family. She's taking time out with, of course, Chandler, her husband, and her beautiful daughter, Grace, and so me being an uncle getting to be in there and be involved, it's just amazing and I never thought I'd see my big sister as a mom. It's just a really surreal and wonderful experience and to have a new family member is just awesome."

Robert, 17, said as Grace's uncle, he's introducing her to as many new things as possible.

"She's at that age now where she's really reacting to things, you know, when she sees a new animal," he shares. "We met a koala for the first time the other day and her little face, she was all kinds of sleepy, and she saw that koala and her face just lit up -- the biggest smile and it was amazing."

"I can already tell she is a wildlife warrior," he adds. "And I cannot wait to just introduce her to everything zoo life."

Above all, Robert is striving to live up to the title of being the fun uncle.

"I'm already trying to teach her how to play the guitar," he says. "It's one of my passions so she'll always go to sleep when I play the guitar. She loves it, so, you know, I'm trying to be the fun Uncle Robert."

Robert joked that although he's taking part in Discovery Channel's popular Shark Week, Bindi will probably want to wait a few years before letting Grace swim with sharks. He described his incredible experience going on a shark dive.

"Well, I think that for me, this adventure, it was probably the most amazing trip I think I've ever been on, you know, for so many reasons," he says. "I got to actually swim with sharks and have them [very close] to my head to see how similar they are. It was the biggest adrenaline rush and an amazing experience, and I cannot wait for you guys to see it."

Robert explained that he had to learn how to keep calm around the sharks since they could sense a person's heart rate.

"But the problem wasn't the fear factor, it wasn't that my heart's going crazy out of fear, it's more that my heart was going so fast out of pure joy and excitement, you know?" he notes. "I was so excited to see sharks firsthand. I wanted to just get as close as possible. And so, working with shark experts Paul de Gelder ... these amazing people that have always worked with sharks their whole life ... they really taught me you almost have to go into this kind of zen state. You have to just sort of calm down -- which is hard for me, because my adrenaline's through the roof -- sit, watch and just try to kind of take it all in."

"Easier said than done when there's a shark coming at ya," he continues. "But I think, as I progress, I like to think I've really become more at one with these animals. I feel like now, and only now, I'm at the point where I reckon I'm getting pretty good with sharks."

Robert's Shark Week special airs July 11 on the Discovery Channel.