New and Looking

[sesame]

I say wise-girl this sounds a little contradictory.

how a person can have an identity contrary to their sex has to do with hormone levels in the womb after brain development and before sex expression

Since we know that sex is determined during the union of sperm and ovum. As the cellulor nuclei combine and fuse their genetic content during zygote formation, sex is determined by the type of chromosome in the donated sperm.
If the sperm is Y type, then the resulting cell will become XY (as the egg is always X) and a male baby will ensue.
If on the other scenario, the sperm is X type, the baby will be female or XX.
The rest of the nine months of pregnancy is just duplication of the same cell bearing the same resulting gene to form the millions of cells that construct this body. Although cells take up different functions and form different tissues and ultimately the various organs, etc. Brain cells, heart cells, bone cells, muscle cells and so on.
My point is sex is NOT determined after brain development, it is done immediately after the fusion of the sperm and ovum.