Isabella could not be aware of the pain she was inflicting; but it was a degree of wilful thoughtlessness which Catherine could not but resent.

James was the sufferer.

She saw him grave and uneasy; and however careless of his present comfort the woman might be who had given him her heart, to her it was always an object.
For poor Captain Tilney too she was greatly concerned.

Though his looks did not please her, his name was a passport to her goodwill, and she thought with sincere compassion of his approaching disappointment; for, in spite of what she had believed herself to overhear in the pump-room, his behaviour was so incompatible with a knowledge of Isabella's engagement that she could not, upon reflection, imagine him aware of it.
He might be jealous of her brother as a rival, but if more had seemed implied, the fault must have been in her misapprehension.

She wished, by a gentle remonstrance, to remind Isabella of her situation, and make her aware of this double unkindness; but for remonstrance, either opportunity or comprehension was always against her.