Gender identity is a new area that needs time to sort itself out so society understands it and manages it properly.
There is no definition of gender identity so how exactly are we to "manage it properly". I have no interest in "managing" how someone presents themselves to the world, they should be free to dress however they like.
The right to decide what gender you are is pretty much accepted, so this person who says they are female needs to be treated as such.
Female is a sex based word, no male can ever be female. What does it mean to be treated as female?
You should Google John Money to find out where the term gender identity comes from. He was a sexologist but was known to refer to himself as a fuckologist, here's the story of what he did to a little boy, one of twins, after a botched circumcision. Both boys later ended their own lives.
allthatsinteresting.com/david-reimer