Final answer:
Mrs. Parsons' children were upset because they were not allowed to go to New York.
Step-by-step explanation:
The event that Mrs. Parsons' children were upset about missing was a trip to New York. It appears that they had a desire or expectation to go there, and the refusal to facilitate this trip led to their discontent.
The passage related to Mrs. Parsons does not provide context as to why the children wanted to go to New York, but it's clear that not allowing them to attend has caused some level of disappointment or conflict within the narrative.