Who carried out the errands of the evil queen in Pushkin's fairy tale?
Apparently, the question here is not about "The Fisherman and the Fish", but all the same about Pushkin's "Dead Princess", where, contrary to all sources (and here is Snow White and Russian folklore), Pushkin introduced a certain "hay girl" Chernavka, who was forced to perform errands of the angry and angry stepmother queen. The image of Chernavka is very interesting from the point of view of establishing a real historical prototype, which is a woman very beloved by Pushkin (well, the fact that he also loves the princess, exclaiming: "My soul," is probably not necessary to say). However, the story about the prototype of Chernavka can take a whole book. Those who know that "they give more for the group" (the term, of course) may not understand - and why, contrary to the sources, where the stepmother, under different guises, hounded the stepdaughter-princess, Pushkin needed to introduce an accomplice in the murder. And such thoughts are good, because they require their explanation from the researchers.
If you mean "The Tale of the Dead Princess and the Seven Bogatyrs", then the instructions of the evil stepmother-queen, who envied the princess's beauty with intense envy, were carried out by her servant Chernavka. But, fortunately, Chernavka performed them with grief in half - she turned out to be more humane than the queen and could not allow the princess to die tied up in the forest.