Joan Winstanley suggests her family only phones her out of duty: may I suggest that she makes an effort to make the conversation interesting, perhaps by taking an interest in the family member who calls? That way, families will enjoy chatting with her and not just ring out of duty.
Charities such as Age UK and Independent Age give advice on how to combat loneliness and lack of human contact. None of this involves relying on family members. If some of this advice is followed, not only will she have something to talk to family about, Joan will have more human contacts and feel less isolated whether or not the family make the duty call.