Dear Eric: I am a 76-year-old man. My best friend is a woman who is 75. Her son and daughter-in-law have an 11-year-old and two little children under three. The son very frequently asks her to provide child-care for overnights and weekends. They are very active and seem to always have plans for ski and bike trips, hiking and camping trips, and out-of-town concerts and visits with friends.