Georgia says she and Caleb were in touch with their family from LA, where they're both based, as the fires developed.
"My cousin was getting evacuated, and she's got a baby, so it's really stressful for all these families," she says.
"They were just waiting to know whether they were going to sleep in their houses that night, basically, and it's a really unsettling thing - and that was just one person's story."
Music is a way to unite people in a time of adversity, says Georgia, and she hopes the show will offer a respite to those who gave their time to the relief effort and those who were displaced by the fires.
"That is what music is - it's an escape from hard stuff and it's a way to confront things and enjoy life and enhance your experience," she says.
"In times like these, music is such a powerful tool to bring people together and make them feel like a part of something and remind them that they're not the only ones who have had to go through this.
"In times like this, feeling like you're understood and that there are other people out there who have had a similar experience to you, can be super comforting."
The Nelson show will now mark the first date of Broods' homecoming tour for their new album Don't Feed The Pop Monster, with shows in Christchurch on March 22 and Auckland on March 24.
Georgia says it's hard to gauge how the album has been received until they play it live - which makes the Nelson show all the more meaningful.
"These are people that have watched us play gigs at breweries when I was 14," she says. "It'll take off a lot of the pressure and replace it with something a little more sentimental so that it feels more of like a celebration.
"We get to share what we've worked so hard on with the people that have seen us trying to make it since we were kids, and at the same time, support them through a really shitty time."