Inmates do NOT have Internet access. However there are some services available for inmates to send their Facebook updates via postal mail to the person/company receiving their requests (and charging for their services) - they will update the pages for the inmate.
https://www.inmateaid.com/ask-the-inmate/does-an-inmate-have-access-to-facebook-to-update-their-account#answer
Accepted Answer Date Created: March 27,2016