"Woman's Day readers adore Kate and her pregnancy and growing baby bump are of huge public interest. The photos of Wills and Kate looking so happy and carefree are lovely," she said in a statement.
"The exclusive set of photos, which also include pictures of the Middleton family and Pippa with a new man, were taken on a public beach by a tourist. They're gorgeous holiday snaps and Kate looks fantastic. It's great to see her looking so healthy and happy after the worrying start to her pregnancy."
Editor of Australian Woman's Day, Fiona Connolly, also defended her decision to run the photos, saying the UK press had a "gentleman's agreement'' with the royal family about what sort of photos will be published - but this didn't apply to Australia.
She said Australia was more laid back as a nation than the British, especially when it came to the beach.
Connolly believed the outcry by St James's Palace was hyper-sensitive.
"In this instance they are a beautiful set of photos," she said.
"As a magazine that does publish photos of the royals, I am sensitive to the sort of pictures that shouldn't be published,'' she said, referring to the 2012 topless shots that appeared in various magazines.
"These (current) photos were taken on a public beach, the Middletons were openly chatting to other holiday makers.
"They are certainly not photos that they would disapprove of - they are happy - and the fact that the last time we saw Kate looking really unwell, coming out of hospital and at a really tough time for her in her pregnancy - to see these photos where she's fit and healthy and really glowing is even more reason to celebrate.''
The couple are expecting their first child in July.
In December Kate was admitted to hospital with severe morning sickness, which pushed the couple to announce the pregnancy.
On news that Chi was publishing the photos St James's Palace issued a statement: "We are disappointed that photographs of the Duke and Duchess on a private holiday look likely to be published overseas.
"This is a clear breach of the couple's right to privacy.''
Connolly admitted the bidding for the photos between several of Australia's biggest selling weekly gossip magazines was "furious''.
Last year Britain's royal family launched legal action against French magazine Closer, over paparazzi pictures of Kate sunbaking in bikini bottoms on the balcony of a chateau in the South of France.
- nzherald.co.nz and AAP
