If there is no fracture she is not lifting because of pain or fear. Might be she had arthritis of shoulder which is unnoticed earlier. Go to near by Physiotherapist and assess her shoulder joint and find out reason behind her not lifting hand.
Next Steps
immediately take an appointment of Physiotherapist nearby and take adequate sessions to bring back her normal Range of shoulder .
Health Tips
If there is no sign of fracture you should not give rest to hand for prolonged time which leads to stiffness later.