https://china.usembassy-china.org.cn/u-s-citizen-services/notaries-public/
Consular officers perform services customarily provided by Notaries Public in the United States. To better serve customers, all notary services in ACS are by appointment only. Please click here to access the appointment calendar.
...
What we can do:
-
Acknowledgement – An Acknowledgement of execution is used for legal agreements, deeds, powers of attorney, business documents, etc. for use in the United States.
As for the content of power of attorney, they need to find out what their purpose is, consult an attorney or ask mortgage/title company (if they are buying a house).