I think our anonymously magely friend meant now a woman, from context.
But this sentiment is also correct. It can be complicated, but if you decide tomorrow that you are a woman, you are a woman just as surely as me. Someone who knew their gender from a young age is just as valid as someone who only recently discovered it, and while there are definitely different experiences living as a cis woman compared to a trans woman, that does not invalidate either of their womanhood. (Ditto trans men, nonbinary folks, genderfluid friends, and so forth.)