A heroine is a woman who has done something brave, new, or good, and who is therefore greatly admired by a lot of people. The national heroine of the day was Xing Fen, winner of the first Gold medal of the Games
The heroine of a book, play, film, or story is the main female character, who usually has good qualities. The heroine is a senior TV executive. = protagonist
If you describe a woman as your heroine, you mean that you admire her greatly, usually because of a particular quality or skill that she has. My heroine was Elizabeth Taylor. = idol