How do I get information on my mother's care when I don't have access?

My mom and stepdad live out of state. She has been diagnosed with dementia and when I talked to her yesterday she told me her legs were not working so she does not walk much. My mom never was big on exercise, preferring to spend her time reading and sitting on the couch. In my heart I have to believe that my stepdad is making the correct decisions regarding her health. But why isn't she walking? Why is she not in therapy if this is a problem? How is her dementia progressing? When she needs to move into assisted living or some other facility, what state will it be in? Why? What if? etc? When I call I only get to talk to my mom so I am sure I am not hearing everything.