] ...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... :-(

A little on line looking around found me a couple of examples from abstracts of documents in the U of Nottingham collection of the papers of the Dukes of Portland.

The 1785 settlement of one of the Bentinck daughters on her marriage to Robert Milnes settles a capital sum of £7500 on her in trust, out of the income of which she receives £150 p.a. (2%) as pin money.

The 1793 settlement of another Bentinck daughter, on marriage to a Royal Navy captain, reserved certain lands in Ireland to produce £200 p.a. in pin money.

The 1795 settlement of the Marquess of Titchfield (heir to the dukedom) and Henrietta Scott makes a charge of £2000 p.a. on an estate in Nottinghamshire for pin money for the Marchioness during her husband's lifetime, with an annuity of £5000 p.a. to her after her husband's death and during her mother's life, increasing to £8500 after her mother dies. (Miss Scott was apparently a connection of the Dundas family, since various Dundases are among the trustees of the settlement). The estate was resettled in 1815 and these amounts were confirmed.

From another source, the 1785 settlement of Mary Robinson on her marriage to Henry Neville, eldest son of Lord Abergavenny, puts lands with an annual income of £2400 into trust, to pay an allowance of £700 p.a. to Henry and pin money of £300 p.a. to Mary; on her father in law's death, Mary's pin money would increase by £200.