Genesis not only uses distinct words for male and female, but also for man, woman, wife, husband, mother, father, son and daughter.
The earliest written documents of Genesis are the Dead Sea Scrolls, which are over 2000y old, and are likely to be copies of even older documents. They are written in the languages of that era, at least one of which has been in continuous use ever since, and has changed so little over the millennia that modern Hebrew speakers still use the same words for male, female, man, woman, wife, husband, mother, father, son and daughter.