Implicating sister → female
Link to implication

Reason:

By definition sister are female. Any other genders wouldn't really fit anyways.

Edit: sisters -> female as well.

Except herms are also referred to as sisters frequently.

Halite said:
Except herms are also referred to as sisters frequently.

Yeah, maybe this wouldn't work. It was just a thought.

Halite said:
Except herms are also referred to as sisters frequently.

Somebody searching for "Sister" is probably not looking for that, though...

Of interest, a search for herm sister brings up 8 posts. At least a couple of them (post #503108, post #351530) have some relevance in this discussion.

-1 for Haltie's same reasoning.

I'm a little herm biased though, so my input should be taken with a grain of salt

If there is female and male and intersex, intersex shouldn't lump in with sister and brother. The sex definitions are pretty concrete. Sibling would work fine though.

Denied for the reasons mentioned in forum #144393.

TLDR: The risk of mistags isn't worth the slight convenience of having it imply female.