Sometimes transitioning to new living arrangements can be very difficult for older adults. She could be suffering from depression, or have a medical condition that is making her feel fatigued and not wanting to engage with others. Has she had a complete physical recently and mental health evaluation? That will help determine what kinds of interventions will help her. Good nutrition, exercise, and social interaction are all important to improve quality of life. Finding senior centers, social groups that take trips, and connecting her with others with similar likes will help and should be encouraged.