My Chapman's edition has a footnote about this, that JA is quoting Mr. Richardson in The Rambler.

"That a young lady should be in love, and the love of the young gentleman undeclared, is an heterodoxy which prudence, and even policy, must not allow. But thus applied to, she is all resignation to her parents. Charming resignation, which inclination opposes not."

I seem to recall that The Ramble was a literary magazine? I'll head over to L&T to ask about it.