If she is going this route, I think it would be best not to interact that much with the initial main lead. She will create situations that would make him fall for her. He will essentially become the second lead. Who knows, it may create a butterfly effect and he ends up being in the accident. Had she not been privy to the story-line and changed her mind, it would be fine. Heart break is a part of life. However, she knows the plot and know he become entangled in it somehow. She should try to avoid the black haired character, while still being respectful. I know these characters tend to avoid and run away from issues in a manner that appears rude. Although, I assume it would be difficult if this is one of those story-lines where the characters are drawn to each other, thereby removing free will, that she can further act to be with the childhood friend.