Red tells Piper Alex Lorna and Frieda that they are her family but they where all selfish and threw Red away for themselves after everything red did for them everyone except Nicky because Nicky showed loyalty and never forgot about the woman who saved her from a early grave stone
And Norma. Norma was loyal too. So was Gina, until Red set her up to get blasted by an oven (by accident). Frieda didn't really do anything to betray Red, as far as memory serves. But other than that, all the betrayal and heartache was what probably made her snap and led to her dementia in the very end. Very sad, Red's ending. Not as sad as Penn's, Taystee's or Poussey's, but still sad.
I realized that in the end Nicky's desire to protect and value others inmates that are struggling is the core of her character that she learned from Red in a prison full of selfish goals it isn't a goal entitlement like Piper it isn't a goal of survival like Alex or Frieda or a goal of love like Lorna Nicky's goal in prison is to not only be free but to make sure that others inmates that are slaves to there addictions are honored and that they matter because if she's doesn't she will feel guilty for the ones that have fallen like Tricia Red Lorna Rosa Tiffany they are watching waiting to see what became of the lifes they lost and that's Nicky's burden