You may not be consciously aware, but you seem to want to be seen as better than her
The question My sister and I are in our 60s and retired. During our teenage years and 20s we were close. In my late 20s, I lived abroad and returned with my now wife. There have always been cultural differences between my wife and my sister that my sister does not make allowances for. My wife can be very direct.
In her early 30s to mid-50s, my sister experienced an abusive marriage ending in divorce. She couldn’t have children and a business failure left her insolvent. She still bitterly resents those 20 unhappy years as a wholly undeserved waste, whereas I have reached retirement with my family, marriage and finances intact.