Even if the Song's Second Madam was the only mistress in the mansion, since she was not the legal wife of the family head, she could at best be regarded as a concubine. Therefore, she wasn't qualified to stay in the east courtyard's main house.
Inside the Song Mansion, the Song family head resided in the east courtyard, which also served as the main courtyard. The South courtyard, the second-largest courtyard after the east courtyard was where Song Ming dwelled. The West courtyard was divided into two parts, one side was inhabited by Second Madam, while the other side was for her two sons. The north courtyard was usually used to receive guests.
So, it was easy for her to find Second Madam's courtyard. Perhaps, either the guards were self-assured or they thought that no one dared to come to the Song Mansion. Therefore, aside from the two teams of night watchers in the mansion, there were only two guards in the courtyard.
