I did, actually, feel quite sorry for her. She looked totally out of her depth/comfort zone - and the way she was clutching at her own 2 month old baby... it was like she was holding a ticking time-bomb, for crying out loud! She's his mother; there is no doubt that she loves Archie - but I don't think she's as "hands on" as they'd have us believe 
Whereas Kate? Engaged with her three (older) children, kept an eye on the older two whilst entertaining the youngest... and there are photos of Kate smiling at Meghan, but as someone else said: Meghan was hiding behind her Hollywood sunglasses, so perhaps she didn't notice/respond/maybe the rumours are true.
My mother and aunt, who are sisters, married brothers. To get them within 50 miles of one another, these days, let alone in the same polo field would require the death of my grandparent. And perhaps not even then. Kate is going to be portrayed as holier-than-thou... because she's going to be our Queen one day; her son will one day be our King. Meghan, on the other hand, is married to the "spare" and gave birth to a child whom the Queen hasn't "gifted" a title to (I don't buy for one second that Meghan would have said "no" to an HRH for her child if it were offered...).
I do feel sympathy for her, though. Because maybe now the lustre is dulling enough for her to realise the dysfunctional family she's married into - something which we Brits have known for decades, but the Americans just don't seem to see... 