There was definitely someone designated to clean such a huge courtyard on a frequent basis. Cui Lao's call got a middle-aged woman running along in no time because her lodgings were near.
She knew how rich these families must be to have such a huge courtyard in the fifth ring of Beijing. She was trained not to ask anything she shouldn't and to pretend not to see anything she shouldn't as well.
Cui Lao got her to leave a complete set of keys and told her that she didn't need to clean for a few days. He got her to leave soon after.
Cui Lao gave the whole set of keys to Ling Yun after she left. "The key to every room is clearly marked. Please stay in whichever room you want to, Young Master. From now on, this courtyard is yours…" Cui Lao beamed at Ling Yun.