Of the three you posted @mathanxiety I love the second (blue) dress. It's really good for her shape as it softens her figure. I think she might go for something covering arms to be on the safe side, at least for inside church. I do love most of M's clothes, just wish she would sort the heels out.
According to the Daily Express online H&M "particularly" wanted the christening to be today but had to reschedule as neither HM nor the PoW were available, so it was rearranged to accommodate the PoW. I don't know where they get their info from, could be bollox.