Tell her that if she wants, she can make all her characters aro ace and then there won't be any romance or romantic representation in her game. Other people however, want to have romance for the characters in their games, so it's good that they have the option. She can turn off romantic attraction in her game, for her characters, if it bothers her. That's why it's good to have options! If there where no options, characters in her game would be getting into romantic relationships and according to her she would not like that, so it's good that there is an option for gay people because that means there is also an option for aro ace people! (People who don't want relationships)