Do I have to change after getting married

My youngest sister are living with my older sisters and she is married to a soccer player that lives out of town. They feel like it’s their house and act like everybody else should just be seconded. However, our brother in law is home for any reason, they feel like my sister changes and no longer defends or prioritize then, as she should according to their believes of how blood bonds should be stronger and unquestionably. I am also married and I believe it is a necessary step towards growing as a new family (wife husband and kids, if) to create limits and house rules that are specifically to the new couple. And also make sure to explain those to the relatives so they know what to expect and above all, how to behave when at your house or around your family. As result some relatives will most likely stop visiting us and start feeling sided. But that is also part of growing, I guess.