If it is a story you don’t know those involved and it is without mention names, it is not backbiting.

I wanted to ask regarding backbiting.Sometimes, when I am with my mum, she might be eager to tell me a story. Before she even starts getting in to the details, I have this feeling that she is going to backbite a person. This may happen with my friends also.They know that I do not like backbiting. But, my mother would probably say to me that she is just telling me something, and my freind might say too me that she is not going to name the person, she just wants to tell me her experience. So where are the boundaries? How will I know when to stop them so they stop backbiting?