Bobbi supports her friend charla, but she thinks that charla is being underappreciated at her job. she thinks she is being , but every time they talk, she brings it up and tells charla to stand up for herself more. charla is starting to get annoyed because it's all bobbi wants to talk about. which rule of friendship is bobbi breaking?

Nagging should not be done

Explanation: Nagging is the activity in which a person starts to find the fault in another person in persistently.This type of behavior in continuous way can lead to irritate or annoy the other person.  

The case mentioned in the question also describes about the nagging behavior showed by Bobbi towards her friend Charla. Bobbi is continuously finding mistake in behavior of Charla that she does not take enough stand for herself in the office. Thus, Charla is getting irritated with this act.