The thing with the polo match is that we only have photographs.I know I'm a bit behind the eight ball! But those photos of her at the polo..pretty sure that sunscreen that many are talking about is the adult Nivea one, in no way would you use that for a baby. That baby should have had a sunhat on, have it's own sunscreen and frankly should not have been in the direct sun, plus should've had a carrier or pram somewhere to have put it down. She has no freaking idea if she just swanned around holding it, poor little thing.
What we know is that there was an event where friends and families of polo players, dressed appropriately, socialised over drinks and picnics and 6's wife turns up looking frazzled wearing some sort of sack.
Anyone who has ever gone anywhere with a newborn will tell you, you get swamped with people cooing, reminiscing and offering help. In the photos, not one single person approaches her, speaks to her, offers her a seat, a drink or to hold Archie. These people are Harry's friends and family. Catherine's busy with her three kids but what about the others?
I think the most likely explanation is that she had already caused a scene before the pictures were taken.