Best Sister Ever

An individual who identifies as a sister to another sibling, who is very clearly not able to be superseded by another sister or person, from inside the family or in any other family. Since there is only one person that can hold this spot, I will save everyone some time and let you know this person identifies as Crystal Kar.....dis.

My sister does so much for me, she is the best sister ever!
Wow, I wish I was him/her, because they have the best sister ever!