I am listed first on mom's POA and Health Care Directive and my sisters listed as second and third on forms. They live a distance away and do not know anything about mom's situation (financial, health, etc.). Since my son helps with his grandma's health situation (ambulance, hospital, doctor appointments, etc) I would like for him to have health care proxy as a back-up to me. Grandma wants it, too. Am I allowed to get that set up for him? Sisters say "no". He is always here and helping with Grandma.