IMO 512.2.1 would cover this and make it a NO:
"Equipment shall be of a design appropriate to the situation in which it is to be used or its mode of installation shall take account of the conditions likely to be encountered".
By fact that her favoured sockets are almost certainly not IP rated and a spillage is highly likely. So the kit is not "of a design appropriate".
Now to the real world, fit the socket then when you're settling up "accidentally" knock your coffee over the socket and say "Told you so!".
I wonder if the next reg 512.2.2 would cover you.....it says:
"If the equipment does not by its construction have the characteristics relevant to the external influences of its location, it may nevertheless be used on condition that it is provided with additional protection in the erection of the installation. such protection shall not adversely affect the operation of the equipment thus protected "
Fit that one double on it's own RCBO and label it "SBS" - tell her it stands for "Special Breaker Socket" (or Silly Bitch Socket).
Good luck!