As a grandmother am I obligated to go over to my granddaughter's house every time she has a crisis?

You sound like you are in a simliar situation that my grandmother was in. In '05 she bought a mobile home and her son and his wife told her that she should move it onto his ranch. Well, she just moved because for the past 4 years she's babysit all 3 of their kids for free for countless hours while they went out and didn't come back sometimes until 3:00 a.m. even though she had been babysitting since 6:00 a.m. that morning. Plus, their youngest has ADD and for a 70-year-old woman to try to babysit 3 kids that have the worst behaviors, you can understand why she finally moved as she could not take much more. You've raised your daughter, your work is done. It is okay for you to be there for your granddaughter but 24/7 is out of the question. Live life, have fun. These are the years in your life where you are supposed to be free, doing what you want to do! So go do them!