Last year MIL pulled the same trick on SIL when traveling for nephew's graduation from basic training. Got in the car for the trip with no money-hotel, food, etc. was required. MIL took no money. Called dh bragging about how she was getting in the car with SIL knowing she didn't have a dime.
Hmmm... if I knew she was doing it on purpose, and bragging about it, I'd be tempted to let her come on my WDW trip (after telling her that she'd need to pay for her room and board) and when she gets there and announces she has no money, I'd say "Oh, that's too bad. Ours was all prepaid and I didn't bring any money either."

My last trip included a couple of extended family members. We all had a fantastic time. The year after that, one of those extended family members went with her daughter's family, and had a horrible time. The daughter is one of those people who doesn't bother to do research, doesn't want to go to the parks early, and doesn't want anyone to do anything without her. Recipe for disaster! If this family member hadn't gone with us first, she would have hated WDW. Now she simply knows to go there with us instead of her daughter.
