Need I explain?

My sister drove me to my son and daughter-in-law's for the last week of my East Coast visit. They moved to Williamsburg, VA last year where my son is a philosophy professor at the College of William and Mary and my daughter-in-law works on campus as well. Once my sister headed home, we drove to do a little shopping at a beautiful yarn shop near her house, and then went to the College to pick up my son.