"They raise children."
Translation:One wychowują dzieci.
Perhaps you had a typo somewhere, because "Oni wychowują dzieci" is an accepted answer, but until a moment ago "One wychowują dzieci" was the only starred answer. So any mistake would get you corrected to the starred answer.
About the (potential) sexist part... do you mean that rejecting this answer would ignore gay couples? Rejecting this answer would first of all ignore heterosexual couples, because a couple consisiting of a man and a woman is undoubtedly "oni".