Deep curtsies really belong to the era of long skirts. It's hard to make one look good when wearing anything else, especially when you have to shake hands at the same time, which Victorian women didn't do. (That was why I was so annoyed at Meghan's wedding curtsey getting missed out of the coverage, as it would have been the curtsey at its best).
TM - cringeworthy. She embarrassed herself and her office with that performance. In her place I'd do a brief bob (and I'd keep my back straight while I was at it).
CP Mary - has it right as usual. Her back is straight and the flared skirt looks pretty.
On the clothes issue - apparently Audi offer a 60% discount to the royal family. If they're doing it, I expect Givenchy can too. But even if Meghan got a 60% discount off every single outfit since the wedding, that's still £300,000 in one season, not counting accessories.