"We haven't had a poll result yet, but there is no doubt in my mind that the electorate will look at this and see it for what it is, which is a cheap shot," Wilson said.
Wilson was brought on as the National Party's chief press secretary after Todd Muller replaced Simon Bridges as leader.
When Muller resigned, Wilson stayed on - serving out a fixed-term contract that ended the day after the election.
Collins said few people would care what Wilson thought of the party.
"Nobody really cares about what somebody who worked here for a couple of months says about a party they're no longer involved in," Collins said.
Collins said she felt she had been "generous" to Wilson.
"Janet was employed by Todd Muller, she was part of his team. I just kept her on, as I did all of her staff, because we were in the middle of a campaign.
"It's the undermining I'm not prepared to accept," she said.
Collins said she did not get lost in paranoia and she disagreed with another of Wilson's suggestions: that she get off social media to improve her focus.
"No, I've got no problem with social media. I don't know what she's talking about," Collins said.
"I'm not distracted at all, I'm focused on the things that matter like Covid-19 and vaccinations," Collins said.
Collins said Wilson might have "struggled" in her press secretary role, as she had never before worked in Parliament - however, Wilson has provided advice to political figures before, including former National prime minister John Key.
"She'd never been a press secretary in Parliament, she didn't know the way things operated here or the long hours," Collins said.
Collins also dismissed the idea she was getting political advice from right-leaning blogger Cameron Slater who said he was still in regular contact with the National leader.
Slater has been distant from the upper echelons of the National Party since the Dirty Politics saga of 2014, when there were concerns about the close association of his blog with the Beehive.
Collins said she was a longtime friend of Slater family, and checked in on Slater's health.
"Obviously Cameron has had very serious health issues and every now and again I'll check on that - just like I rang Todd Muller regularly during the campaign when he had had his breakdown - because that's the sort of thing good people do," Collins said.