Julianne Hough's brother ''couldn't be happier'' about her engagement.

The 'Dancing With the Stars' judge is set to wed after hockey player Brooks Laich recently popped the question and her 30-year-old sibling revealed he proposed at the end of a family vacation.

Derek told the Insider: ''[I'm] so excited.

''We actually spent the week at the lake house and all the family was there, the kids, nieces and nephews. And we spent the most magical, amazing week together and then at the very end [they] got engaged.

''He's a great guy, I just couldn't be happier for them.''

Though Brooks hadn't confided to Derek that he was planning to propose, the dancer ''kind of'' had an idea what was going to happen after he witnessed the sportsman having a heart-to-heart talk with his future father Bruce.

Derek explained :''He went to my dad. They locked themselves out on a deck -- they were out there for a good two hours talking so I kind of had an idea.

''I was like, 'Oh, OK. I see what's happening!'''

Julianne, 27, announced she and Brooks, 31, were engaged on her Instagram page.

The 'Safe Haven' star broke the news on her account by posting a photograph of herself staring at her ring while wrapping her arms and legs around Brooks on a balcony overlooking a lake.

She captioned the picture: ''We are overwhelmed with joy and excitement to share with you our recent engagement. #fiancé #love.''

Julianne - who was previously in a relationship with Ryan Seacrest - started dating the Washington Capitals player in February 2014 after being set up on a date by a mutual friend.