You arranged your family’s vacation all by yourself and didn’t thing twice when your daughter decided she didn’t want to go with you. She can get a little testy anyway, sometimes. So you asked your niece to take her place and just assumed she could use your daughter’s airplane ticket. Not so fast, auntie. The security agent at the gate was super nice when she explained what the airline ticketing rules are but that didn’t help when you had to call your sister to tell her to come pick up her daughter. Thanksgiving dinner conversation might be a little testy this year.