Perhaps it's part of a fictional or horror story. In horror, there are often concepts that defy normal morality and this could be one such extreme concept where a character has done something unthinkable like actually eating a friend, which would be a very dark and gory plot point.
Well, it might be a sign of a psychological breakdown in the narrator of the story. Eating a friend is an extremely abnormal act, so it could imply that the person has lost their grip on reality and normal social and moral boundaries.
Another possibility is that it's a misphrasing. It could be that your friend helped you out in a really big way, like when you were in a tough situation, perhaps at school or work. Your friend came to your rescue and did so much for you that it was as if they 'ate up' all the problems for you, making the situation better.
On the other hand, it might be that your friend took over something that was yours in a rather forceful way. Like if you had an idea for a party or an event, and your friend took that idea and ran with it, making it their own and leaving you feeling like you'd been pushed aside or 'eaten out' of your own plan.
There are several factors to consider. First, think about your privacy. If your story contains personal or sensitive information, are you comfortable with this person seeing it? Second, what is your relationship with this person? If it's a positive relationship and you don't mind sharing your story, then adding as a friend could be fine. However, if you have any doubts or concerns, it's better not to. For example, if you're using social media for professional networking and this person seems a bit sketchy, it's probably best to decline.
If your puppy 'ate' something unusual, like a sock or a small toy, it can be a very scary situation. The first time my puppy ate something he shouldn't have, it was a small piece of plastic. I immediately called the vet. Thankfully, it passed through his system without any problems. But it was a nerve - wracking experience.
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.
The impact could be positive. If the story is inspiring, it might encourage your friend to be more selfless or more committed to their beliefs. For example, if it's about a missionary who helped a lot of people in a poor area, your friend could be motivated to do some volunteer work.
In a Cinderella - like story, being a friend could mean being there for someone who is in a difficult situation like Cinderella was. It might involve offering support, kindness, and not being judgmental. Just like how the fairy godmother was a friend to Cinderella by helping her get to the ball.