The Misses Steele would not be hanging around Exeter, on numerous trips, at their own expense.

Ch. 21 says that the Middleton's invitation was to take place, "as soon as their present engagements at Exeter were over." That means that they were already visiting some (less wealthy?, certainly not landed, if they lived in town) relations or friends, and they only 'traded up,' as it were, from one set of hosts to a better.