A lot of female protagonists are mary sues, the most recent and easily recognisable one from popular media would be Rey from disney star wars. Perhaps tht's something you're picking up on, there are plenty of well written femal protags however, just have to find the right book.
As for the sex of the author, that does not matter, and should never be considered when buying a book.
If anyone tells you otherwise they are unequivocally a sexist and highly bigoted.