I'm back tracking a bit, but I wanted to go back to my disappointment in Catherine and her thoughts and theories about the general.

In Chapter 22, we have this, with regard to the cabinet:

She felt humbled to the dust. Could not the adventure of the chest have taught her wisdom?

And then this:

Why was Miss Tilney embarrassed? Could there be any unwillingness on the General's side to shew her over the Abbey? The proposal was his own. And was it not odd that he should always take his walk so early?

How is that odd? Just because it is not what she is used to doesn't mean there is anything nefarious about it.

Then she jumps to this conclusion:

The General certainly had been an unkind husband. He did not love her walk: - could he therefore have loved her?

and then:

A portrait - very like- of a departed wife, not valued by the husband! He must have been dreadfully cruel to her!

I know she is young, but obviously she does not know enough about grief to see that different people grieve in different ways, and that indifference does not necessarily mean cruelty.