People pleasing and my family

Hello coaches!
So I feel like I’ve come so far when it comes to the people pleasing thing except around my family. I noticed that I act a certain way around them and find myself being a little bit upset afterwards because I am not being real. I am “lying”. It is such a default and don’t want to ruffle any feathers especially around my sister. She is 6 years younger and I feel like the younger sister. And I don’t like it. How do I just be me and let her be her even though she may not like this newer version of me. I don’t think it’s that she won’t like it but she will be a bit shocked for lack of a better word. She is also a bit sharp sometimes so I just keep the peace so as not to upset her. Thanks so much!