This is not a straightforward question. Ultimately, as adults, spouses are legally responsible for themselves, and inter alia, for their offspring. The military has statutory responsibility in some areas - e.g. in housing they have to ensure that repairs are done; in BFG they have to ensure that child protection policies are in place. The military provides various support services to assist families - for example, at my unit I am the initial point of contact for families of deployed personnel, and my function is mainly to provide information or refer to other agencies. I am not Families Officer.
Do you have a specific scenario in mind? PM me in confidence if you like.