"He is very good on this," Collins said.
Woodhouse will now be given the Pike River Mine Recovery portfolio.
He will also get regional development.
He will keep associate finance and will remain deputy leader of the House.
Collins said Reti is a doctor, a specialist and "has even worked Harvard".
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Woodhouse is a "top performer" and is an important part of National.
Collins said the matter has "now been resolved" and Woodhouse is happy with his portfolios.
"The public was rightly appalled," that Covid-19 data was leaked.
As to other portfolio shake-ups, Collins said there were still conversations to have.
She will be making calls today.
"Sometimes people can't always have what they want.
"We have a fabulous team."
Collins said there is "no suggestion" that Muller got any information from Boag.
She said it was time to "move on" and win the election.
She said Reti has shown himself to be an excellent performer in the House.
She said it is her belief that no other National MPs have any leaked information.
Collins said a more full reshuffle will be announced tomorrow.
She said it was more difficult divvying up portfolios than receiving them.
Collins supported the Prime Minister's planning, which would implement regional lockdowns rather than a country-wide lockdown.
She said Woodhouse is "utterly delighted" with the outcome.
"We need to move on," she said, adding that it wasn't acceptable to have received the leaked data and not pass it on to the Minister of Health.
"I have no doubt at all that Michael will never make that mistake again."
She said she can't remember the last time she spoke to Cameron Slater.
But she said who she speaks to is her private business.
Asked who was the National base, she said: "All right-thinking people - love them".
Back on Woodhouse, she said she still has "huge confidence in him".
Collins said she had talked to Woodhouse about the story of the homeless man sneaking into a quarantine hotel.
She said that he confirmed that that information came from a different source than Boag, who provided him with the Covid-19 data.
Collins said Woodhouse still stands by his source.
She said it is still National's view that the Government should not be charging people coming back to the country to go into quarantine or isolation.
She said the Government needs to do a better job when it comes to contact tracing.
"I don't think they have been that good on selling it," she said.
She added that Ardern is an "excellent communicator" and she should find a way.
She said there has been a degree of mixed messaging.
"I think she's right to think about a plan," she said, in regards to this morning's new lockdown plan.
Collins said the Government does have a role in the Pacific.
But she said "Australia has a real problem," in reference to a new Covid-19 outbreak.
It's not safe to open a travel bubble with Australia, she said.
"It's all about safety."
She said it is better to move safely and slowly, but not too slowly.
Earlier Collins said that any changes in her caucus would be "mild" and that there would only be a few shifts when it came to portfolios.
Speaking to media this morning, Collins downplayed the significance of any of these changes, saying it would only affect herself, her new deputy leader Gerry Brownlee and "a few other people".
She did not say who these other people would be, but the future of health spokesman Michael Woodhouse is in question.
Last night, Collins confirmed Paul Goldsmith would keep finance but, when asked about Woodhouse keeping health, she was non-committal.
Collins said there were "still a few things to work out" in terms of what comes next for Woodhouse.
After she was announced as leader last night, Collins marched down to waiting media with almost every single National MP.
It's likely to be a different picture when she addresses media on Parliament's black and white tiles this afternoon.
Meanwhile, Prime Minister Jacinda Ardern does not appear to be too worried about her new political foe.
She said this morning that she accepts that there is an election this year and that there will be politicking, but her focus is on the pandemic.
"My time, my energy is focused on Covid-19."
Ardern said politicking will not mean much to New Zealanders, who will be expecting the Government to focus on the Covid-19 response, and she hasn't spent much time thinking about squaring off with Collins.