The miniature Christmas lights that can be seen on the tree in the drugstore, and in with the Christmas decorations that Addie's father brings home, did not exist in 1946. This type of Christmas light was not introduced in America until about 1950, and didn't really become a dominant force in holiday lighting until the 1960's. The light strings that would have been used in 1946 would likely have been 8-bulb sets using c6 bulbs, or 15-bulb sets using c7 bulbs.
There is a painted backdrop of the school visible through Addie's kitchen door in at least one scene. However, the outdoor location shooting shows that the school was located in quite another direction from her house; there's no way it could have been seen through her kitchen door in that shot.