Well I have no problem in saying that this is an absolutely lovely project, and that it's exactly the kind of project Kate should be getting involved with and should be doing more of. I have nothing but praise for the project and her involvement.
However (and this is NOT a slam on Kate but on the behaviour of the press and fans) it is yet another example of the hypocrisy and double standards. Kate's received an excessive level of near-universal praise for a book which realistically she had a fairly minimal involvement in. Meghan wrote a whole book, and has received little but abuse for it (false accusations of plagiarism even after the other author released a statement saying there were no similarities; newspapers trying to coerce published authors into give quotes decrying Meghan for the purpose of inventing material to smear her with; the Telegraph writing that ludicrous article claiming Meghan has single handedly stopped a generation from reading!). It's a double standard, and it's not anti-Kate to point out that Kate is held to such a different standard.
The other elephant in the room. Clearly Kate has a genuine passion for photography and is decent at it. It's not a Brooklyn Beckham situation. But there is another important factor which has to do with money and control. The reason KP has Kate take the official photos of the children is because she then owns the copyright, which means the press don't financially benefit from those photos. It's an old tactic which many celebs use, and which the press absolutely hate because they lose money. Nothing wrong with wanting to own the copyright of photos of your own children, and not wanting the press to financially benefit from your kids, but Kate isn't some ordinary celeb. She's a Royal. The BRF have long had an unspoken "I'll scratch my back and you scratch mine" arrangement with the press, and access to royal children is part of that deal. If you do research, it's insane the ways the BRF accommodate and give the British tabloids special access, and how much they cooperate with the tabloids and try to keep the tabloids happy. I mean Buckingham Palace literally throws special private parties just for tabloid editors and senior reporters. One of the reasons the press turned on Harry and Meghan is because H&M refused to honour this unspoken contract. People sometimes act as though all this royal drama is purely ideological, but really a lot of it is about money. The press lost a lot of money - money they were counting on - over Meghan's insistence on keeping Archie mostly out of the public eye, and believe me they've lost a absolute fortune over Megxit. There's one tabloid photographer who's literally rage-tweeted that he was planning to put his children through private school on the money he assumed he'd make off of Meghan and how he's been financially screwed by her leaving. And right now Meghan's drawing all their venom but in the past they've been hostile towards Kate for the same reason. When KP first started releasing Kate's copyrighted photos, the tabloids responded by writing some very nasty articles about Kate to send a message to her to play along and stick to the deal. Now I have to give the Cambridges credit, they've done a great and very savvy job of walking a fine line between keeping the press happy, and retaining some control. But please remember this is not just a case of some ordinary loving mum who just happens to really enjoy taking pics of her kiddies. It's a calculated media strategy where an entire PR team have actively worked to create this "Kate as a dedicated photographer" persona, for financial and media-control reasons.