Unity is key during any crisis. Strive to pull the family together, despite any disagreements or rough circumstances. Define the roles that everyone can play to help your sick loved one. Take turns talking and helping - this way everyone shares the responsibility and no one becomes overly exhausted mentally or physically.
If you're terminally ill allow your family and friends to support you and provide comfort during this rough time. Do not worry about members not getting along, instead embrace this time and make the most out of it. Be a family.