I am not sure if this is already knewn but I haven't seen a report for this. So I wanted to mention it. I know that the new Kami is the very first female in this game. And I have seen that there was a bit of a gender trouble for the first 3 or 4 users that have earned Carpo but that is now fixed.

But as I looked in the pet search the older Kamis up, I have seen that a few of them turned into females as well. I have seen 4 female Pestilences, 1 female War, 1 female Death, 3 female Famines, 2 female Cat of Saturn, female 3 Shantaks and 1 female Butterfly Dragon.

There's 17 non-Carpo Kami that are females. However I don't see any connection between them or their owners and the current event progress of their owners. Are you sure that their owners didn't change them to females with Change Sex scroll? If they didn't, we need a bit more info to find out how this happened, i.e. when approximately the gender was changed.

The female gender of Carpo herself wasn't coded at the event start, so she was a default male for the first few users before we added a code that creates female Kami for the current event instead of male. This was reported here and then fixed, but this code can't affect the existing pets in any way.

I didn't know that it was possible to change the Kamis sex by yourself, I feel a bit stupid now.