But the proposal that the monarchy should be more "representative" strikes me as ridiculous. Unless I am completely missing something, the concept of a hereditary title is inherently incapable of producing anyone "representative" or, for that matter, diverse.
the ironic thing is that there is nothing more representative then the RF. they represent the government, the church, the military, the nation and the commonwealth.
the Fabian Society hasn't actually said that the RF themselves are too rich and white to be representative of modern Britain....but that's what the writer seems to be inferring with her article.
if you want them to be genetically diverse they are already that. the joke is to call them Germans but they are actually descended from way more countries then that. if it had a monarchy (and what country hasn't?) then the RF can probably claim decent from it. they are very well bred mutts.

if you want them to be racially diverse
right now....tough beans because unless they fall in love and marry someone from outside their usual set of their own free will its impossible.

you could try forcing their hands at it. the law already says they cant marry catholics. but i think its rather unlikely that a modern government will agree to make a new law saying members of the RF can only marry non-aristocratic people who are darker then beige (self-tanner not counted).

what the Fabian Society
does say on diversifying them is....
To make the monarchy more representative of a diverse Britain of four nations, many cultures, many faiths and no faith, the report also recommends: ending the historic ban on non-Anglicans, or anyone who marries a Catholic, succeeding to the throne, and the preference in the succession given to younger brothers over elder sisters; and ending the position of the head of state as Supreme Governor of the Church of England.
you can read the Fabian's plans here....
Fabian Society calls for overhaul of monarchytheir plans don't so much diversify and modernized the monarchy as it makes them religiously, socially and politically obsolete. which is no doubt the real goal.