Sharing such stories is completely inappropriate and violates moral and ethical boundaries. This involves vulgar and inappropriate content that should not be spread or discussed in public or private in a positive way.
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.
Since I'm not sure exactly what is meant by 'ate out my mom stories', but if it's about eating out with mom, an example could be going to a pizza place and mom insisting on trying a new, strange - looking topping.
Well, without more context, it's difficult to say precisely. 'Ate out my mom stories' might be stories where the narrator went to eat at a restaurant or some place outside with their mom. It could involve things like the conversations they had during those outings, or perhaps some funny incidents that occurred while they were out eating.
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.