Actors create the Character’s backstory (history, experiences). This best serves when it is hooked into what the Character is doing and why the Character behaves as they do in the current moments of the script. Also how it pertains in the Character’s motivation.

This is a very good grounding exercise. However, don’t play it and don’t make all of your decisions because of it. For example: you might discover that you and your sister and brother have always argued and that they have always criticized you. That’s the history and the scene itself seems to fortify this thought. To compound things, you have a sensitive issue to discuss with both of them.

Now, here’s how to work with that. Instead of playing into that history of relationships, create a scenario where you are constantly looking for an opening. Notice anything they do that could be interpreted as a soft, kind or lenient moment and work into that. Use that as an opening to speak to them. This will work even if your line of actually discussing the issue comes a few moments later. Look for the openings, the times that are different and not historic, even if they never come.