Although, i did read some things wrong, i think the part about having xy and being a woman is not one of them. The Swyer syndrome, or XY gonadal dysgenesis, is a condition, in witch babies with xy chromosomes cant develope testicles, and thus get female characteristics. They then get born with those characterristics and live as women for their entire live. I would say that those people are, without a doubt female. Please read the article for more information about it.  The reason i brought this topic up, is to show that chromosomes cant always be used to define the gender of someone, and can be really wierd overall.  I didnt ask you IF sex is determined by chromosomes. I asked you HOW that works. The exact process how the chromosomes controll every aspect of sexual development in humans.