Your power-of-attorney has nothing to do with anything related to his prison sentence. Parole eligibility is determined by the sentencing language from the judge. You may call the facility and ask to speak to the inmate's counselor or case manager to see if they have any information that they will share.
https://www.inmateaid.com/ask-the-inmate/how-do-i-go-about-finding-out-when-my-husbands-parole-date#answer
Accepted Answer Date Created: February 04,2016