Before, when Xu Qingyin led her servants to pay respect to the host and have a drink around the host's table, there were a lot of people doing the same thing which made the place a little chaotic.
Her pearl was most likely lost during that time.
At the table, Madame Song heard the commotion and instantly ordered her people to look for the pearl for Xu Qingyin. Since it was likely lost around the host's table, they focused the search for it around there.
Everyone started to search but nobody could find it.
In the end, a somewhat annoyed voice said, "I noticed Lu Jiao crouch down just now. She seemed to have picked something up."
Everyone turned to Lu Jiao.
Initially, Lu Jiao didn't think too much about this. She truly believed Xu Qingyin lost her pearl. Now she realized this whole thing was to drag her down.
If she didn't realize that by now, she would be a real idiot.