...but was always under the impression that a lady's pin money was fixed in her marriage settlement, and therefore it should be posible to look at marriage settlement paperwork of the time and make some deductions from those examples. And If I had any examples to deduct from, I'd share them... :-(

Some other impressions I have is that pin money was simply a personal allowance, for clothing, trinkets, gifts, books or whatever the lady fancied. It wasn't really related to any household expenses, so the grandness of the household wouldn't change it much, except perhaps to demand grander dresses.

I have also assumed that the reference at the end of P&P to Mrs Darcy making small economies so that she could occasionally provide Mrs Wickham with a little financial support was a reference to Lizzy's use of her pin money. Traditionally, pin money is very much the lady's own , and the husband wasn't supposed to question her use of it.