I found this book at the flea marked, entitled The Lady's Letter-Writer, which has form letters for just about any event a Victorian-era lady might expect, and which might require a letter.
Such as 'Requesting a Friend to Execute a Commission,' and 'on receiving a Miniature from Her Suitor,' etc. etc.
The book is not in sellable shape, so I've decided to treat you, my faithful followers, with one letter from the book every Thursday, for your entertainment and edification.
Letter IA young Lady, in Answer to the Proposal of a Gentleman who had met her the previous Evening:
Hempstead, July 5th, 18--Sir:-- Although it is the highest compliment that can be paid to our sex, to receive offers calculated to ensure a lasting acquaintance, I must still complain of the preciptate character of your address to one who, till last night was a total stranger to you. Without wishing to say anything harsh, I must confess that I do not feel any motive to entertain so hasty a proposal, and have felt bound to lay your letter before my parents, as I could not think of concealing from them any correspondence of such a description.
Trusting that you will see the matter in its proper light,
Now, wasn't that interesting?