My first thought was not that Charles is a boy who became woman. I don't know why, but I immediately thought of genetic disease - Non-Klinefelter XXY.
47,XXY is a chromosomal arrangement where a person has 2 X chromosomes and 1 Y chromosome. The apparent majority of individuals with the XXY karyotype are males and some of those are considered to have Klinefelter syndrome. However other individuals use estrogen and identify as female (some are born with a female phenotype and with SRY negative 47,XXY) and some 47,XXYs choose to be androgynous, and use no hormone treatment. The choice of identification and hormonal or surgical treatments may follow gender identity counselling. It is not known what percentage of 47,XXYs identify as male, as female, or otherwise.
These individuals identify or choose to identify as women, take estradiol. Some of them can and have been documented as bearing children. There is no syndrome for an XXY person who identifies female; their breasts, hips, and lack of testicular phenotype-associated features are considered normal. A very small number of XXYs not born with female genitalia, generally designated male at birth, actually go through the process of feminizing transition. It would appear that more choose to adapt to the fluidity of their gender than to make a physical transition from one binary to the other
Maybe that would be a better explanation, I don't know. But to me the transgender thing, with a child who changes sex during teen years, was very odd