After Bindi Irwin shared the exciting news of her marriage to Chandler Powell on Wednesday, her younger brother Robert posted a touching note describing how excited he is for the couple.
"Bindi and Chandler, words cannot describe how happy and proud I am that today you started your married life and celebrated love during a difficult time for our world," the 16-year-old wrote in a post featuring his sister's wedding photo.
The couple's wedding ceremony took place hours before a new restriction in Australia went into effect, which limits weddings to just five people, including the couple, the witnesses and the celebrant.
Bindi and Chandler chose to make it a small ceremony, without guests, because of health concerns amid the novel coronavirus pandemic.
MORE: Bindi Irwin marries Chandler Powell in 'small ceremony' at the Australia Zoo without guests"Even though all of your wedding plans had to change at the last minute to keep everyone safe and healthy, it truly was an emotional and beautifully spontaneous day," Robert Irwin wrote in his message to his sister and Powell.
"I was beyond honoured to get to walk Bindi down the aisle today," he shared.
The two share a very tight-knit bond and frequently post about their close family on social media. Last year, Bindi Irwin told ET why it was so important for her younger brother to walk her down the aisle.
"I'm always so grateful that Robert is there, and he has been such a big part of my life and he's always stepped up and been the one to give me a hug when I need it and encourage me forward in life," she told the outlet. "He will definitely be the one to walk me down the aisle when the time comes, and I think that will make it really special."
In his post, Robert Irwin also mentioned how his sister honored their father's memory on her special day.
"I know that Dad was with us, and we are all so delighted for your future as husband and wife," he wrote. Bindi Irwin described in her wedding announcement that her family lit a candle in her father's memory at the ceremony. She said their family shared, "tears and smiles and love."
Bindi Irwin was clearly touched by her brother's heartfelt message. "Love you so much, Robert," she commented on his post. "Thank you for being there to walk me down the aisle. You mean the world to me."