The same video on IG a couple of days ago had lots of comments about Catherine being too rude/high and mighty/princessy/uncaring to help the man. She was actually wise to stay back and let William and others help him (someone who's just fallen usually needs a bit of air), and not make a fuss which would have likely embarrassed him. She was also considerate to not completely turn her back on the person she was talking to, especially when he didn't move.
Rachel would have laughed, and then poked her nose in (and tongue out), exhibiting fake concern and embarassing the dignitary instead of letting him move on with grace and humour like he did.
Juvenile idiot, perfect for Sparry.
Now I'm getting flashbacks of her clapping like a confused "delicate" seal at the polo ceremony
ETA: She could be useful about now in India. Mosquitoes are back and they've been mostly immune to our candles and sprays and other forms of repellents for a while now. We can go the old-fashioned way and have her kill them by hand.
Her tongue can help too.