How common is it for siblings to be estranged?
The number of Americans who are completely estranged from a sibling is relatively small—probably less than 5 percent, says Karl Pillemer, a Cornell University professor.
Can you legally disown your sibling?
There is no “legal” way of disowning a sibling. However, you can cut her out of your life. The “how” is really pretty simple, you just stop being anywhere your sister is and stop communicating with her. But think carefully about how you will go about this.
Why do siblings become estranged?
Sibling estrangement is an outgrowth of “drifting apart and taking different paths. The more painful (breakup) is when it comes out of a conflict or many conflicts,” Kennedy-Moore said. Often cutting off the relationship arises when one sibling “finds it toxic to have that person in their life,” Kennedy-Moore said.