Terri Irwin Is 'Very Happy' About Daughter Bindi's Engagement: 'Steve Would Be Too'

Terri Irwin couldn’t be more excited about welcoming Chandler Powell into the family.

Terri, 55, congratulated her daughter Bindi Irwin on her engagement to Powell on Wednesday with a heartfelt post on Twitter.

“Best day ever! Chandler asked and beautiful @BindiIrwin said yes,” she wrote.

The mom of two also gave a sweet nod to her late husband Steve Irwin, saying he would be equally as excited.

“I am so very happy, and I know Steve would be too. Congratulations!!” she concluded.

Powell popped the question on Bindi’s 21st birthday.

The conservationist shared the news on Twitter on Wednesday, posting two photos of herself with her longtime love. In one photo, Irwin and Powell share a sweet hug, while in the other, Irwin gives a close-up look at her stunning engagement ring.

“On my birthday I said ‘yes’ & ‘forever’ to the love of my life,” Irwin, who celebrated her 21st birthday on Wednesday, captioned the sweet snaps. “Chandler, close to 6 years ago I fell in love with you & every day since has been a whirlwind of adventure & true happiness.”

“Here’s to a lifetime of friendship, purpose & unconditional love,” she added.

Irwin tells PEOPLE exclusively, “I am overjoyed to be sharing the news that Chandler and I are engaged! This has been the most special day celebrating my 21st birthday.”

She adds, “I’ve met my soulmate and I can’t wait to spend the rest of my life with Chandler. We’ve been together for nearly 6 years now and he’s my happily ever after.”

Powell, too, tells PEOPLE that the engagement was “the most perfect and beautiful day of my life.”

“After Bindi’s birthday celebration at Australia Zoo, we had a photoshoot organized to celebrate her turning 21,” he reveals. “Just before we started the shoot, I took her to a special part of Australia Zoo to ask the girl of my dreams to become my wife. These past five years together have been the best of my life and we look forward to a lifetime of magical moments to come.”

Irwin and Powell, 22, met in November 2013 when he was in her native Australia for a professional wakeboarding competition and decided to stop by the Australia Zoo, where the Irwin family lives and works.

“It just so happened that Bindi was giving tours that day,” he recalled to PEOPLE in December. “I’m like, ‘Wow she is amazing.’” The pair “hit it off right away,” he said, adding, “We haven’t looked back since.”

Bindi told PEOPLE she couldn’t be happier to have found a partner who shares so many of her father Steve Irwin‘s qualities. “He loves wildlife and conservation and he has this strength. Which is necessary when you’re jumping on crocs,” she said.