With all the Hollywood-styled holiday stories (and videos), this is a simple, beautiful tale set in the recent past. I have one treasured copy I read to my students. Each year I get choked up. It is a long enough story to be read in segments. In a teacher's opinion, it is an excellent study of vocabulary, character, setting, and mood. For the non-teacher it is just plain great reading.
I cannot recommend this story enough. Even second graders become emotionally involved with Ivy's plight. There is a video version, "The Wish That Changed Christmas", but it's difficult to find.