] that makes sense, but I never would have come up with that myself (although it might become clearer later in the book?)

Yeah, I think so, and sorry if I've "spoiled" something for you! :-<

Isabella gives Catherine several hints about her preference for James before he appears on the stage which fly right over poor Catherine's head.

Besides the one above, there's

Ch 4: "How excessively like her brother Miss Morland is!"

Ch. 6: "...Nay, I cannot blame you"--speaking more seriously--"your feelings are easily understood. Where the heart is really attached, I know very well how little one can be pleased with the attention of anybody else."

Ch. 6 - in describing the kind of man she prefers: "Well, my taste is different. I prefer light eyes, and as to complexion--do you know--I like a sallow better than any other. You must not betray me, if you should ever meet with one of your acquaintance answering that description."

"Betray you! What do you mean?"

"Nay, do not distress me. I believe I have said too much. Let us drop the subject."

While I can't recall a physical description of James, he is said to look much like Catherine and she is described in Ch. 1 as having "sallow skin".