I'm trying to think about how reparations might be paid and by whom.
There is a focus on this thread on the Royal Family, but this was not the only family which benefitted from slavery. Some 3,000 persons were paid compensation for the slaves (i.e 'property') they 'lost' at abolition in 1834. Do we have to trace their descendants and demand reparation money from them? How about the descendants of those who made huge fortunes in the 17th & 18th C from slave owning, but who may have given up their plantations before 1834? Or those who dissipated the fortunes made by their forebears, such as William Beckford in the early 19th C who managed to run through a massive fortune derived from plantations in Jamaica.
There is a school of historical thought which claims that the sugar trade was in decline in the late 18th, early 19th C, and indeed, some of the compensation money was never 'enjoyed' by its recipients, but went straight away to pay off the debts they had incurred while struggling to keep their plantations going; would we have to trace those creditors and demand money from them? It seems to me to be a tremendously complex area which requires more than just a simplistic 'The Queen should give them some of her money' solution.
This wiki page might be of interest. It details known slave traders, slave owners and owners who received compensation, with links to individuals:
en.wikipedia.org/wiki/Category:British_slave_owners
Or, do we just say that, as the money been dispersed widely throughout Britain over the past 3/400 years, it is the responsibility of the nation as a whole to make proper reparation?