According to China's household registration management system, my sister can move into my sister's household registration. According to the People's Republic of China (PRC) Household Registration Law, brothers and sisters can transfer their household registration, but they must meet certain conditions. For example, a sister needs to have a stable place of residence and legal housing, and she needs to provide relevant supporting documents when moving, such as ID cards and household registration books. The application for relocation also needs to comply with the regulations and procedures of the local public security organs. Specific operations, you can go to the local police station to understand the relevant requirements and go through the formalities.