quite ready

The etymology of the word “quite” is curious. It is as folows:

quite (adv.) c. 1300, “completely, altogether, entirely, wholly,” adverbial form of Middle English quit, quite (adj.) “free, clear”. Originally “thoroughly;” the weaker sense of “fairly” is attested from mid-19c. In Middle English the adverb also could be quitely, quitelich, quitli (c. 1300).

So in this context, quite ready means completely ready and not “fairly ready.”