Female is related to male only by marriage.
The word female is a diminutive, the way that novelette is a diminutive of novel —it is a shorter novel. Female is not a diminutive of male, even though females are usually shorter than males, which is a sad joke and I apologize. Female ultimately comes from a diminutive of the Latin word femina —in Latin, femella meant “little woman,” and it came to English through French as femelle.
So female readers don’t feel slighted, the word male also comes from a Latin source— mas —and the diminutive masculus, meaning “little man,” which eventually came to us through Old French as male.
Because the concept of femelle is so closely related to that of male (related but opposite, as you may have noticed), we began altering
the spelling of femelle to coincide with the spelling of male. Not surprising, actually. Just more proof that opposites attract.