Its kind of weirder than that because of the (mad) wording they used.
"'Female' means a person belonging, at conception, to the sex that produces the large reproductive cell. 'Male' means a person belonging, at conception, to the sex that produces the small reproductive cell."
That fries my brain on so many levels.
Firstly nothing is producing sex cells at the moment of conception. Conception is the moment the sperm and the egg join. It then undergoes division, into firstly, undifferentiated cells. All foetuses develop along female lines until 6 weeks or so, but even then, neither is producing sex cells. And whilst, ultimately, women are born with all the eggs they are going to release over their lives, spermatogenesis does not begin until puberty in males.
So, is everyone female until puberty?
The mind boggles.