I hate being defined by my relation to other people. My mother continues to call me Sis to this day and each time she does I seethe inside. I have mentioned my feelings on this to her, but she will be calling me Sis to her dying day.
I am not alone in my feelings. It reminds me of when the preacher at my grandmother's funeral gathered those closest to her to get some content for her eulogy. He had never met her in life. He asked about her life and said something about her being a mother and housewife in a way that indicated he thought she could be defined by those labels and was going to build a eulogy around that. There were several sharp intakes of breath, a few derisive snorts and then a rush of laughter and exchanged glances as we all imagined just how she would be cutting this preacherman off at the knees on hearing that. I believe it was my father who spoke first and said approximately, "No, no, we would not say that. I don't think anyone would ever describe her that way." Someone else added under their breath, "Not if he wanted to live." She would not let anyone call her Grandma unless they had a valid claim to. She would firmly correct them if they tried.