I agree, I think she is picking her own clothes, and off the shelf, although clearly high end, they are not tailored to fit her. Unlike Kate who has a dresser, seamstress and stylist, and whose clothes I think are tailored to fit her.
I do just think she’s also not confident in dressing for high profile events where she is trying to be royal. When she goes paired down, like the blue dress in the rain she gets it right, but when she goes too far like the green ensemble, it’s like she watched downtown abbey and decided that’s what a duchess wears.
the green would probably have worked if it fitted and she lost the massive cape. It was just too much. And it’s never good when you can see the outline of your underwear.
if I was her, I’d side eye what Kate does, as she’s had a lot of experience now, clearly has a stylist , and in recent years has been getting it right. I’d also employ a stylist and seamstress if I was her.
its hard though, I don’t envy her at all, as when you know you will be massively photographed, I’d probably fuck it up too at times. The temptation to over think it and try too hard.