Character Analysis
Hunilla is less a character than a secret. Melville says that "two unnamed events" (5.147) befell Hunilla on the island after her husband and brother died, leaving her alone. What are those events?
You can't know for sure, of course. But the suggestion is that Hunilla was pregnant when her husband and brother died. She marked out 180 days on a calendar, which would be about six months—time enough for her to give birth, if she was a few months pregnant. She then stopped keeping record of the days. This suggests that she was in despair because her baby was still-born.
The second event is connected to other ships; the Captain asks Hunilla "did no other vessel pass the isle?" (5.140), and she says no, but hesitatingly. The implication is that a vessel stopped on the island, and a sailor or sailors raped her.
"Those two unnamed events which befell Hunilla on this isle, let them abide between her and her God," the narrator says piously. (5.147) But of course he's already hinted at them strongly. Refusing to say them makes them a secret; something the smart, attentive reader gets as a kind of gift. The trauma becomes more exciting and important because it is hinted at, rather than spoken (if he had really wanted to not speak of it, he could have just not spoken of it, right?)
Hunilla, then, represents the barrenness and violence of the Galapagos—a barrenness and violence that remain unseen secrets. Only those who read this travel narrative closely can truly understand Hunilla, and the islands.
Hunilla's Timeline