Cloud and Townsend, "Safe People", chapter 13 "Should I repair or replace?", pp. 195-196:
5. Give change a chance.
Many times people will get tired of what they have been putting up with in a relationship, and finally "get some boundaries." Then their first real exercise of boundaries will be to end the relationship. We see this often in marriage. One passive partner will get a stomach full of the other person's character problems and finally say, "Enough!" And then they will file for divorce.
They will often say that this is an exercise in "boundaries," but in reality it is a cop-out. Boundaries in a relationship are not real boundaries unless someone can exercise them in the relationship. To say that you now have boundaries, and then leave, is to not have boundaries at all.
A person with true boundaries would go back in to the relationship and take stands on the individual problems that come up within the day-to-day relationship. This is the true test of boundaries, to be in the relationship and not be controlled or abused anymore.
There are two reasons to work on boundaries within the relationship. The first is to take responsibility for one's own character. The real test of our character is to do the difficult things while in the difficult relationship, not to leave it. That is where the hard choices are. It takes a lot of courage and character to deal with a difficult person in the right way. We can only know that we have done the right thing and that we truly have character when we have been tested in the fire of relationship.
In addition, facing up to a difficult relationship is also the only guarantee that one will be able to do the right thing in a new relationship. Many times people leave one bad relationship without ever learning to do the right thing and just go repeat the cycle over again in a new one. They have not changed in the fire; they have only left the fire. That is not real change, and they are setting themselves up for failure again.
The second reason to give change a chance is that we never really know if the relationship has a chance until we begin to do the right thing over time. When one person changes, the relationship changes. In our experience, many difficult situations have been turned around by the character change of one party forcing change in the other. This is true in friendship, business relationships, family relationships, marriage, and dating. Therefore, before you leave a relationship, make sure that you begin to implement your changes in the relationship. Then you will know what is really there.
So, applied to your relationship with your sister, this staying in relationship and giving change a chance could mean that you begin by having a conversation with her about what happened during your visit. About how she waited until midnight when everyone was tired then picked a fight with you. How this was not acceptable to you. How you will not let it happen again: until you are sure she accepts that this is a big deal for you etc, you will not stay overnight in her home. You cannot control her behavior but you can and will control your exposure to her behavior.
Good for you, by the way, for going home in the middle of the night.