The SSAFA are an Armed Forces charity who offer life long support to imprisoned serving members of the armed forces, veterans and their families. They can provide prison in-reach services which may help families who are unsure about things like making contact, setting up a visit or other prison systems or regulations.
Families can contact SSAFA and check their eligibility for support.
W: https://www.ssafa.org.uk/help-you/veterans/support-offenders-and-ex-offenders