Han Yu had originally intended to accompany his own daughter-in-law, but since the Old lady harbored some concerns about Han Yu and knew that this grandson wasn't an easy bone to chew, she only called for Han Jincai and his wife and Su Wenyue to come over.
Su Wenyue also had confidence that she could handle that old woman and didn't need Han Yu to accompany her, letting Han Yu stay with his other brothers instead, to avoid gaining a reputation for following his woman around. Su Wenyue knew Han Yu had a bit of male chauvinism in him, and she was willing to save face for her man; outside, she still paid close attention to these matters.