And she is mortally offended with Mr.Franklin Blake.

Very good again.

Here (I say to myself) is a young lady who has lost a valuable jewel--a young lady, also, as my own eyes and ears inform me, who is of an impetuous temperament.

Under these circumstances, and with that character, what does she do?
She betrays an incomprehensible resentment against Mr.Blake, Mr.Superintendent, and myself--otherwise, the very three people who have all, in their different ways, been trying to help her to recover her lost jewel.
Having brought my inquiry to that point--THEN, my lady, and not till then, I begin to look back into my own mind for my own experience.
My own experience explains Miss Verinder's otherwise incomprehensible conduct.

It associates her with those other young ladies that I know of.
It tells me she has debts she daren't acknowledge, that must be paid.
And it sets me asking myself, whether the loss of the Diamond may not mean--that the Diamond must be secretly pledged to pay them.