Who is Sister Yang in "Eternal Dragon Slayer"?

According to seniority, Zhang Wuji called that person's elder sister. When Zhang Sanfeng was a teenager, Yang Guo and his wife were both over 30 yuan and over 40 yuan. This is not too much to call uncle. Yang Guo and his wife's son are the same generation as Zhang Sanfeng, and Yang Guo's grandson is the same generation as Zhang Cuishan. Of course, the sister Yang Zhang Wuji met was Yang Guo's great-granddaughter.