You are right. If people would read the LAST LINE of her letter they would see she is a Believer. I have always felt that Santa Clause overshadows the true meaning and reason for Christmas, celebrating the birth of our Savior, Jesus Christ. I think Santa Clause just confuses children about the real meaning of Christmas, just like the Easter Bunny at Easter.
Neither Santa or the Easter Bunny confused me or my sister about what we were celebrating. On Christmas Eve we read about Christ's birth from the Bible and then we went to sleep in anticipation of Santa. On Easter we went to Sunday School and Church, came home, ate dinner and took a nap while the Easter bunny came.
My son had no problems with believing in Santa or the Easter bunny. Just like me, he wasn't traumatized when he found out who they really were.
I'm an atheist and I tell my children adults invented Santa Claus so children will behave and go to bed early in the winter while the adults get drunk and fornicate with each other.
In fact, I instruct my children not to lie and to tell others the same thing if asked about it. I don't lie to my kids.
Now if you think that is bad, lie to your kids all you like and they will lie to you.
I don't want my kids to lie to me, and they expect the same from me...