At the beginning of Chapter 9, JA writes, "Elizabeth passed the chief of the night in her sister's room, and in the morning had the pleasure of being able to send a tolerable answer to the enquiries which she very early received from Mr. Bingley by a housemaid, and some time afterwards from the two elegant ladies who waited on his sisters." (emphasis mine)

Were the two elegant ladies callers on the Bingley sisters, or were they lady's maids?

According to David Shapard's annotation, they were lady's maids and were referred to as "ladies" as a tribute to their elegance. Somehow, I don't find that convincing.

Also, in her six adult novels, this would be the only example, out of about 20, of JA using "wait on" other than as meaning "to call on."

That the inquiry seems to have come from the ladies themselves, rather than from the Bingley sisters through the ladies, also suggests to me that they were callers rather than maids, since JA specifically says that the housemaid was inquiring on Bingley's behalf. Would the Bingley sisters' lady's maids have been inquiring, on their own behalf, after the health of a guest?

On the other hand, who were the callers that they would have inquired after an unwell guest? And while the time is not clear, it sounds like it was still morning -- too early for guests?