But Bennett defended Upston's performance and said she was wise not to wade into every public debate.
"At all times Louise defended women. There's no two ways about it.
"What she often didn't do is comment on individual cases where she didn't have all the facts. And in some of those cases, we saw it play out that there was a different side to the story that wasn't in the public at the time."
Bennett was referring to a scandal in which players from the Waikato Chiefs rugby side were alleged to have groped, thrown gravel, and sworn at a stripper during an end-of-season event in September.
Upston said at the time she would not comment on individual cases, angering some MPs. Some of the stripper's allegations were later denied by independent witnesses in an inquiry held by the NZ Rugby Union.
Bennett said she would be a strong advocate for women and would only speak out "where I think there are definitely wrongs".
"But I've learned in my previous portfolios there is always another side and one does have to still do that with caution."
Upston also copped flak for not calling herself a feminist. In the past, Bennett has said she is a feminist on some days and not on others. But she was firmer today, saying she would proudly claim that title.
She traces her feminism back to her youth, when she was forced to stick up for herself against two older brothers. She was particularly aggrieved when her brothers were given shotguns for their 16th birthdays and she was given a sewing machine - which she later traded it for a motorcycle.
"I'm not sure I'm quite as active as marching down the streets as I was in my youth," Bennett said. "But I can still get quite worked up about a sense of unfairness for other women now as opposed to for myself, because I think I'm in a really privileged position.
"So in that context I would call myself a feminist."
National has typically found it harder to appeal to women but that changed under Prime Minister John Key, who polled better among women than his predecessor Don Brash. As Key leaves Parliament, Bennett's appointment could be seen as a way of keeping women voters onside.
Bennett said that was one benefit of her promotion, but she added she "did not do anything for cosmetic reasons".
"I hope it does a good message out there. But equally I think it's my actions and what I deliver that people will respond most to."
Her top priorities in the role will be advocating for victims of family violence and helping to progress landmark pay equity changes. These objectives tied in with her other portfolios, State Services and Police.
Last month, the Government agreed to change the law to allow women to file claims with employers instead of going through the courts.
"I have been doing quite a bit of work on pay equity and inequality and so I'm really keen to keep going down that track," Bennett said.
"I have a real sense that I want to continue the work for those women that are in lower-paid jobs and really being treated a bit unfairly, I think."
She is pleased with progress in the public sector, where 45 per cent of senior leaders are women. But she admits some areas "still need further work".
Bennett has also held on to her Climate Change portfolio, and has taken on the Tourism portfolio. She has given up the Social Housing portfolio to Amy Adams.
