The elder Miss Steele uses it too. Reading this thread, I knew at least one other JA character used it too, but couldn't remember which novel it was from, so had to use the JA novel search page to track it down. LOVE that feature!

"I'm sure there's a vast many smart beaux in Exeter; but you know, how could I tell what smart beaux there might be about Norland? and I was only afraid the Miss Dashwoods might find it dull at Barton, if they had not so many as they used to have. But perhaps you young ladies may not care about the beaux, and had as lief be without them as with them."

Don't know if there's any significance to the fact that Wentworth uses "lieve" and Miss Steele uses "lief", or whether it's just JA being indifferent about the spelling.

I couldn't help but notice JA's use of "lief" and "lieve" (in addition to Mr. Bennet's use of the word "missish") because they always struck me as rare instances of her use of the kind of words that regularly pepper the dialogue of modern writers of regency era novels ;-).