“I took the liberty a few days ago of asking your Black velvet Bonnet to lend me it’s cawl, which it very readily did, & by which I have been enabled to give a considerable improvement of dignity to my Cap, which was before too nidgetty to please me.”

Cawl—Born with a veil (cawl/caul) over your face. (Ask Jeeves UK) I am guessing it is a veil or netting which hung forward on the face?

Nidget—A fool, an idiot, a coward. (Webster’s)

If only people could be as amiable as these head covers—I find this way of relating her activities extremely amusing and have not laughed as much since forever.