In the 1760s a movement towards abolishing vails was begun in Scotland.

Rioting footmen resulted, in London and in Edingburh, disturbing theatre performances and at public places like Ranelagh pleasure gardens.

However , the movement against vails giving continued, and in A Picture of England( 1789) , M. D'Archenholtz, the Prussian visitor to these shores wrote that the practise was almost entierly abandoned.

But...

In some hosueholds the practise remianed,and this may account for JAs uncertainty as to the ammount she needed to leave poor Richis.

Elizabeth Austen( nee Bridges) may have continued the vail giving that she expereinced in her owm family home( and as Rowling was on the Goodnestone estate, no doubt the family traditions would be contiuned.)

If I may, I'll quote from The Domestic Servant Class in the Eighteenth Century by J. Jean Hecht, whihc summarises the position nicely:

Nevertheless there long remained a conisderable number of houses in which it( givign vails-JW) continued to be practised. As late as 1778 Hutchinson who described it as having been laid down "almost eveywhere" found that it was kept up at Lord HArdwickes and some upper class families continued to maintain it well into the nineteenth century. Among the higher clergy and the judiciary it was especially tenacious. In certain sections of the middle calsses it also lingered for a considerable time.Declaring in 1771 that vails-givign was "not suffered in any genteel families" a writer made clear that the custom was still prevalent among small merchants and tradesmen. He supposed however that " fashion and a reputation for politness" would eventually " bring over those vulgar families" that continued to preserve it. His expectations were largley realised in time ; but in 1785 the Rev.Trusler could still write " Though vails are abolished among the first class of people they are not so among the second".
pp165-6.

So no wonder JA was in a quandry as to what to leave for Richis.