I had a situation a few years ago where DSD had just turned 10 in October and we were going on our first WDW trip in December. The trip was going to be the majority of her Christmas presents from us. Also, her father was out of work and would not be able to provide any presents at his house. She was used to "Santa" coming to both houses. I didn't have the heart to just tell her, so, when she brought "Santa" up shortly after she turned 10, I said, "Oh! Didn't you know?!" She said, "Know what?" I said, "Once a child turns 10, he/she drops off Santa's list because he has more babies being born every year to deliver to and he can't deliver to everybody forever. Why do you think
we don't get gifts from Santa?" That made perfect sense to her and I didn't have to be the one to tell her. It also covered for the situation at her father's house. I know it was the coward's way out, but...