My edition of Persuasion has quite a long note on this.

Miss Larolles is identified in Cecilia as "one of that numerous tribe of young ladies to whom all conversation is irksome in which they are not themselves engaged."

It has Cheryl's quote, preceded by:

"At a concert in London, Miss Larolles tells Cecilia that she has not been able to speak to Mr. Meadows, as she wished."

From what Cheryl quoted, it continues:

" (Miss Larolles still talking) 'It's the shockingest thing you can conceive to be made sit in the middle of those forms; one might as well be at home, for nobody can speak to one.' (Vol IV Ch. VI) During the same scene Cecilia experiences a misunderstanding with Delvile, the hero of the novel, because of his belief that she is engaged to another man."

The note goes on to point out that Cecilia is one of the exemplary novels JA mentions in Northanger Abbey in the 'defense of the novel'. Then the note finishes with this:

"There are some general comparisons to be made between Cecilia and Persuasion: in each novel a level-headed but socially and intellectually isolated heroine finds herself in a household where the extravagant owners will not 'retrench', and therefore get into financial difficulties; and in each the matrimonial hopes of the heroine are adversely affected by the rigid opinions of a man with parental authority over her, who cares for nothing but rank and status."