Yu Ziyuan (虞紫鸢, Yú Zǐyuān) was the wife of the former leader of the Yunmeng Jiang Sect, Jiang Fengmian, and the mother of Jiang Cheng and Jiang Yanli. She also went by the titles Madam Yu (虞夫人, Yú fūrén) and the Violet Spider (紫蜘蛛, Zǐ Zhīzhū). She had a cold and assertive personality which did not come off as likeable. She was a formidable cultivator whose name alone could scare quite a few people away. She had a poor relationship with Wei Wuxian, as she viewed him as the cause of all problems that befall her family. She would often speak poorly of him in her conversations with Jiang Fengmian.

(Source: Wikipedia, Mo Dao Zu Shi Wikia)