Laowen is your big brother(you were adopted) and you were kidnapped before his parents died and he went to the ghost valley. The both of you had been separated but in truth, you were saved by ye baiyi and he raised you. Once ye baiyi found out about wen ke xing, he helped the both of you meet again but he had only introduced you as his maid because he wanted you to do what you felt comfortable with and reveal yourself truly to laowen when the time comes