DEAR ABBY: I work and have a family and live five hours from where I grew up. My mom isn’t in the best health and neither is her husband. While I try to visit as often as I can, she always wants me to visit more often, which I understand. The problem is, she keeps asking us to leave our 5-year-old son with her for long weekends or to spend a week with her and her husband. They are good people, but…