It seemed like Fred and Joachim were suitably friendly/affectionate on the day for me to think that perhaps things have settled a bit. Mary and Joachim greeted each other as well.
It's not odd that Marie stayed with the children in DC as it was a constitutional event. Benedikte and Joachim participated in their official roles. Fred and Mary's children were there as children of the new King (and Christian as new Crown Prince, of course).
Mary wore elements of the Rugby Parure on the day (brooch on belt, earrings and hair pins) which means that she will be keeping it - makes sense as the tiara has been adjusted to suit her, and of course it has great personal history with her as well.
Daisy wore the ruby horseshoe pin which was a gift from her father on the day legislation was changed so that she would, in time, become Queen.
She wore it for her own proclamation as Monarch.