Scenario: mum of 3, including one newborn (less than 3 months) gets asked to host an Xmas do because she has the largest house.
It's agreed that all will bring something to lessen work for said hostess and a course is assigned to each guest/ household - including, of course, the hostess
Said hostess has certain dietary requirements - let's say she's vegetarian, for instance
The dessert-bringing guest produces something that the hostess will not be able to eat and makes a point of saying "well, you won't be able to eat it."
Should the dessert-bringing guest, in the knowledge of the hostess's dietary limitations, have ensured that her contribution was appropriate for all, or not?