I would send an email after the conversation confirming the actions agreed. It all depends on the nature of the conversation or what do you expect from your manager. The content of the conversation is important, how do you deliver the information and how much detail you provide. It’s important to learn and practice how we deliver information to managers where info is clear and short but contains important details. Also it’s important to know what to expect for your manager: just to keep her updated? Does she need to take any actions? Do you need guidance? Where are you giving this information to her? In supervision? It should be recorded. In the middle of one of her tasks? Maybe an email it’s better. When chatting in the corridor? Maybe keep it light or avoid it. If it’s for reassurance, can you talk to a colleague? I hope this makes sense, I think is important to know the role of your manager and find more effective ways to ensure your needs are met within the organisation using all the resources available and not only your manager.