“Do not be frightened, my dear Catherine,” whispered Isabella, “but I am really going to dance with your brother again. I declare positively it is quite shocking.
"A young woman did not dance more than two pairs of dances with the same man or her reputation would be at risk. Even two dances signaled to observers that the gentleman in question had a particular interest in her" (Maria Grace,“The High Stakes of Etiquette for Young Ladies in the Regency” ).
Milsom Street
A street known for its stores and shopping in the 18th century until the present. "Milsom Street became one of the most prestigious shopping areas in the country" (Paul Eanuelli, "The City of Bath as a Character"). 
country–dancing
"A rural or traditional dance, esp. in England and Scotland; spec. one in which couples begin by standing face to face in long lines" (OED).
cotillions
"The name of several dances, chiefly of French origin, consisting of a variety of steps and figures" (OED).
sword–case
"A case to hold a sword; in mod. use, a receptacle at the back of a carriage for swords, sticks, or other articles" (OED).
Curricle
"A light two-wheeled carriage, usually drawn by two horses abreast" (OED).
Did not we agree together to take a drive this morning?
“Do not accept an invitation to visit any place of public amusement, with a gentleman with whom you are but slightly acquainted, unless there is another lady also invited. You may, as a young lady, go with a relative or your fiancée, without a chaperon, but not otherwise” (Florence Hartley, The Ladies' Book of Etiquette, and Manual of Politeness, 173).