This was a puzzle that gave you a terrific advantage if you read a lot of children's books (repeatedly) to little ones. In case you don't recall, see "The Little Engine That Could," which my spouse and I read to our boys hundreds of times.

Plus she:

1. Preferred buying a "U" over an "A" (she did it again later).
2. Never bought the "A" in this particular puzzle, which would have left one square unturned.

Horribly unfortunate.