!spoiler Ah? I didn’t catch that, I thought they divorced when the daughter was still alive given the parts about dating someone else? Where in the story did you catch that bit?

I think you explained it quite well. I just read the story and was a bit confused by the ending but this clarified it for me.

Major spoilers ahead! (struggling with the spoiler tag!)

!spoiler The story reads like she’s in the present and you assume her memories of her daughter are in the past. Then looking back at the language used, she’s describing memories of her daughter with language that indicates it’s in the future, not the past. So it stands to reason that the encounters with the heptapods are in the present and learning their language gives her the ability to ‘see’ the future I assume Gary is her daughter’s father. Just like she mentions of the readers of the Book of Ages, she won’t do anything to change the future even if she knows what’s coming, even if it means a future where her daughter dies young.

Ogtha

Except XX male syndrome is a thing, where externally individuals present male but have female karyotype. So are those people female despite having functional male genitalia? And that’s only one of a myriad of situations where an individual’s chromosomes don’t reflect what their phenotype is like nor their biological reproductive function. Chromosomes are NOT an infallible indicator of biological sex.

Also the text of the law says nothing about chromosomes. It indicates from conception the cells that produce the large gamete are considered female, and cells that produce the small gamete are considered male. No one is producing gametes at conception. It also completely disregards anyone who produces no gametes at all. At best this law has declared everyone to have no biological sex whatsoever.