Why are only foreign brides acceptable for the Danish royal princes?
Someone wrote here that allowing a Danish woman to marry into the family would create problems, and they'd get a situation like the BRF have the with Middletons.
Bringing in a foreign bride supposedly avoids the problems. Her family and background won't create problems for the DRF. Only Marge doesn't understand the internet, how it revealed Mary's past and true self to the world; and didn't count on the bride's family arriving in Denmark and pushing their way into royal engagements.