Final answer:
The provided excerpts do not offer any information about Mrs. Lu or Hsaing-ling or the reasoning behind changing seating arrangements. The texts cover different stories and characters with no connection to the question asked.
Step-by-step explanation:
The passages provided do not contain any information regarding someone named Mrs. Lu or her interactions with Hsaing-ling. Rather, the excerpts cover various events and characters from different narratives. In one, there is a reference to the wife of Hong Pansa, who, along with another concubine, employs the services of a sorceress to disfavor their husband's son, Gil-Dong.
Another passage describes a Mrs. Linde preparing for visitors in what seems to be a scene from a play or novel. Additionally, there are descriptions of various social and personal dynamics among characters such as Dagget and Louisa, and in a separate narrative, there is a comment on the burial of Gil-Dong's father.
Without specific text discussing Mrs. Lu and Hsaing-ling, it is not possible to provide an answer regarding Mrs. Lu's reasons for changing seating arrangements.