Spider Spirit Fourth Sister is absolutely particularly beautiful. And the story between she and the Destiny One so touching, we got some clues and thoughts why.
Since she was born in a poor single family and is shy about expressing emotions. She is stubborn on the surface and rejects people thousands of miles away, but she is kind to the people of Destiny One. She praises him for his intelligence and longs to be recognized and loved by him. She helped the Destiny One many time in the game. She saved the Destiny One and gave him her bed to sleep on. She gave the Destiny One medicine to heal his injuries and gave the Destiny One a lot of treasure boxes (she got a dowry).
In the original novel Journey to the West, there is no emotional line between Wukong and the White Bone Demon.
Time goes to Black Myth Wukong, Game scence team would like a happy love story so they made Spider Spirit Fourth Sister to make up there regrets in W-game, one clue is that unlike other sisters, she bunned her hair which means married, anyway, she is very very beautiful, strong but miserable in the end. But maybe the end is not a real end. There is a high probability that she is the introduction to the DLC Heavenly Court.