There is, no doubt, subliminal communication going on between Anne and CW.

Since immersing myself in the Master & Commander series (I'm up to book 14), and reading some of the non-fiction that supports the novels, I have started to think like Captain Aubrey. ;-) The detail in these stories enables me to take an educated guess about why CW objects to a family or group of ladies, as opposed to one lady living on board.

On most ships, the only "comfortable" and large cabin is the captain's. The larger the ship, the more likely he would be to have a suite of rooms, including dining parlor, sleeping quarters, etc. If you have one woman on board (not the Captain's wife), or perhaps two, they can bunk in together, and the Captain would move to quarters around the Gunroom where the other officers sleep. But if you have more ladies, where would they all go? If you displace the officers from the gunroom, they would be hanging hammocks with the crew. This might be done in an emergency situation, for ladies of some social status, but I can't see it occuring otherwise.