The back of the card says:
Molly's mother helped the girls make Halloween costumes. She showed them how to make hula skirts from newspaper and green crepe paper.
When they went trick or treating, the girls got apples, doughnuts, molasses kisses, peanuts, popcorn balls, and their favorite treat. What was their favorite treat? To find out, change each letter to the one that comes after it in the alphabet:
Snnsrhd Qnkk Onor
Answer: Tootsie Roll Pops
This is maybe my favorite part of Molly's story. In second grade, I insisted on copying her costume for Halloween, even though it was much too cold for it!