Her brother, James Wypych, also defended his younger sister, saying she's just a normal teenager "living her life".
"She's been singled out because she's a big name right now," James said. "I don't think she should be hated and ridiculed, though, for something that is quite common.
"Sure, it's underage drinking and that photo with the other girl holding the cannabis, I can see how that would look bad.
"But I think people have to understand that in New Zealand it's quite common for people her age to be drinking and doing drugs. People younger than her drink and do drugs and I think that's more of a worry."
Rosanagh has kept a low profile this week.
TV3 has now confirmed she will remain in the show, saying it had "reviewed Rosanagh's role in the show and is happy that she takes part in the live final on Friday".
Texts to Hawke's Bay Today have been overwhelmingly in support of Rosanagh, but some called for her to be disqualified from tomorrow's show.
One labelled Rosanagh as a bad role model and said: "that inappropriate behaviour comes with a price. I think TV3 should be sending a message here."
The controversy did not appear to harm Rosanagh's chances of winning the competition, with a poll on NZNTM's Facebook page showing her a close second to favourite Brigette.
Rosanagh admitted to a drink-driving conviction earlier this year, but this week media revealed she had two more police convictions, for driving while disqualified and giving false information to police.
TEXTS TO THE EDITOR:
* Rosanagh Wypych, you are most certainly no role model.
* Re our HB Next Top Model - hopefully people stop slagging her. Get a grip, it's hard enough for teens these days. Some adults forget about their teens. To the parent of the 11-year-old Facebook user: Kids have to be 13 to be on there - worry about your own child .
* Rosanagh should be taken off Top Model as a role model for our young girls. That inappropriate behaviour comes with a price. I think TV3 should be sending a message here.
* What's with the witch hunt on Rosanagh Wypych? Leave her alone - she's doing really well on NZNTM. Great for Hawke's Bay. Not her holding the "cannabis" and love the "concerned parent " comment. Jealousy rears its ugly head again. Go Rosanagh: Best of luck for Friday.