Her brother-in-law has led a personal crusade against poaching and protecting vulnerable wildlife.
So Pippa Middleton's decision to enjoy a plate of whale meat on holiday may have been rather difficult for Prince William to swallow.
The 31-year-old, who styles herself as a food and lifestyle writer, has told of eating Minke whale - even though it is largely banned worldwide. She boasted of tucking into the delicacy in Norway, to the horror of environmental campaigners who say she is helping promote an "unimaginably cruel" trade.
In a gushing newspaper feature, the Duchess of Cambridge's younger sister described how the smoked meat was served in a "wonderfully convivial atmosphere" at the Juvet Landscape Hotel in north-west Norway.
Tucking into a starter prepared carpaccio-style - raw and very thinly sliced - she wrote: "We dined on smoked whale carpaccio (which tastes similar to smoked salmon but looks more like venison carpaccio)."
Earlier she had enjoyed a steam bath and rubbed ice on her body in a "snow spa" at the upmarket hotel, where she spent the night in a £170-a-night 'designer pod'.
The hunting and importation of whale meat is banned in Britain, as it is in most parts of the world, by both the International Whaling Commission and by the international wildlife convention CITES.
But Norway - as well as Japan and Iceland - has exploited legal loopholes that allow it to opt out of regulations. Last year it killed around 730 Minke whales, the highest number since it broke the moratorium on commercial whaling in 1993.
Campaigners have long called for a crackdown, arguing the hunting process is
"unimaginably cruel and inhumane".
Even with modern harpoons powered by explosives, the mammals often died a "slow and painful" death.
Critics said Miss Middleton's decision to eat whale meat was at odds with the stance taken by Prince William - even though he too has been attacked for continuing to hunt wild game.
She has also been photographed hunting in the past.
Vanessa Williams-Grey, of Whale and Dolphin Conservation, said: "It might have been better for Pippa to take a whale watch trip in Norway.
"She might then have thought twice about condoning and indeed, promoting, this cruel and unnecessary trade."
Philip Mansbridge, UK director of the International Fund for Animal Welfare, said she was "unwittingly setting a bad example" that may encourage other tourists.
A spokesman for Miss Middleton, who travelled on the junket for the Daily Telegraph, refused to comment last night.
But Knut Slinning, owner of Juvet Landscape Hotel, said he had no plans to stop serving whale meat because it has been eaten for "many hundreds of years".
However, Siri Martinsen, of Norway's animals rights group NOAH, said Miss Middleton has a "special responsibility" not to support animal cruelty.
- Daily Mail