This is a very disturbing statement. However, without more context, it's hard to say exactly what occurred. It could be a figure of speech, like in a very competitive or cut - throat situation where one person 'took' something important from another, metaphorically 'eating' it. Or it could be part of a fictional or horror - inspired story.
Well, if it's a horror story, it might be about a deranged man with a cannibalistic urge who targeted someone's son. It could be set in a spooky, isolated place like an old mansion or a desolate forest.
It's hard to say without more context. She could be anyone from a friend who took over a conversation you were having about a story, to a classmate who maybe used your story idea for her own work.
It could also be a very unique way of saying that a girl had a strong impact on your story. Say you were writing a story and she provided so many ideas or changes that it was like she devoured the original concept and replaced it with something new.
No, it's not a common type of story at all. Normal stories usually revolve around more common themes like love, adventure, friendship etc. This phrase seems very strange and not something you'd typically find in mainstream literature or storytelling.
There was a novel that matched the plot of a man eating a fox fairy, and that was " Abducting a fox fairy to be a husband." This novel told the story of the male protagonist accidentally eating the inner core of the Fox Fairy, causing the Fox Fairy to have no choice but to live with him. The male protagonist often caused trouble, and the fox fairy quietly solved his problems. This novel might meet your requirements.