The following is an annotated version of the fairy tale. I recommend reading the entire story before exploring the annotations, especially if you have not read the tale recently.
ON A HIGH pasture land, near an immense precipice, some maidens were occupied in spinning and attending to their grazing cattle, when an old strange looking man with a white beard reaching down to his girdle approached, and said, "Oh fair maidens, beware of the abyss, for if one of you should drop her spindle down the cliff, her mother would be turned into a cow that very moment!"
So saying the aged man disappeared, and the girls, bewildered by his words, and discussing the strange incident, approached near to the ravine which had suddenly become interesting to them. They peered curiously over the edge, as though expecting to see some unaccustomed sight, when suddenly the most beautiful of the maidens let her spindle drop from her hand, and before she could recover it, it was bounding from rock to rock into the depths beneath. When she returned home that evening she found her worst fears realized, for her mother stood before the door transformed into a cow.
A short time later her father married again. His new wife was a widow, and brought a daughter of her own into her new home. This girl was not particularly well favored, and her mother immediately began to hate her stepdaughter because of the latter's good looks. She forbade her henceforth to wash her face, to comb her hair or to change her clothes, and in every way she could think of she sought to make her miserable.
One morning she gave her a bag filled with hemp, saying, "If you do not spin this and make a fine top of it by tonight, you need not return home, for I intend to kill you."
The poor girl, deeply dejected, walked behind the cattle, industriously spinning as she went, but by noon when the cattle lay down in the shade to rest, she observed that she had made but little progress and she began to weep bitterly.
Now, her mother was driven daily to pasture with the other cows, and seeing her daughter's tears she drew near and asked why she wept, whereupon the maiden told her all. Then the cow comforted her daughter, saying, "My darling child, be consoled! Let me take the hemp into my mouth and chew it; through my ear a thread will come out. You must take the end of this and wind it into a top." So this was done; the hemp was soon spun, and when the girl gave it to her stepmother that evening, she was greatly surprised.
Next morning the woman roughly ordered the maiden to spin a still larger bag of hemp, and as the girl, thanks to her mother, spun and wound it all, her stepmother, on the following day, gave her twice the quantity to spin. Nevertheless, the girl brought home at night even that unusually large quantity well spun, and her stepmother concluded that the poor girl was not spinning alone, but that other maidens, her friends, were giving her help. Therefore she, next morning, sent her own daughter to spy upon the poor girl and to report what she saw. The girl soon noticed that the cow helped the poor orphan by chewing the hemp, while she drew the thread and wound it on a top, and she ran back home and informed her mother of what she had seen. Upon this, the stepmother insisted that her husband should order that particular cow to be slaughtered. Her husband at first hesitated, but as his wife urged him more and more, he finally decided to do as she wished.
On learning what had been decided, the stepdaughter wept more than ever, and when her mother asked what was the matter, she told her tearfully all that had been arranged. Thereupon the cow said to her daughter, "Wipe away your tears, and do not cry any more. When they slaughter me, you must take great care not to eat any of the meat, but after the repast, carefully collect my bones and inter them behind the house under a certain stone; then, should you ever be in need of help, come to my grave and there you will find it."
The cow was killed, and when the meat was served the poor girl declined to eat of it, pretending that she had no appetite; after the meal she gathered with great care all the bones and buried them on the spot indicated by her mother.
Now, the name of the maiden was Marra, but, as she had to do the roughest work of the house, such as carrying water, washing, and sweeping, she was called by her stepmother and stepsister Pepelyouga.
One Sunday, when the stepmother and her daughter had dressed themselves for church, the woman spread about the house the contents of a basktetful of millet, and said, "Listen, Pepelyouga; if you do not gather up all this millet and have dinner ready by the time we return from church, I will kill you!"
When they had gone, the poor girl began to weep, reflecting, "As to the dinner I can easily prepare it, but how can I possibly gather up all this millet?" But that very moment she recalled the words of the cow, that, if she ever should be struck by misfortune, she need but walk to the grave behind the house, when she would find instant help there. Immediately she ran out, and, when she approached the grave, lo! a chest was lying on the grave wide open, and inside were beautiful dresses and everything necessary for a lady's toilet. Two doves were sitting on the lid of the chest, and as the girl drew near, they said to her, "Marra, take from the chest the dress you like the best, clothe yourself, and go to church. As to the millet and other work, we ourselves will attend to that and see that everything is in good order!"
Marra needed no second invitation; she took the first silk dress she touched, made her toilet, and went to church, where her entrance created quite a sensation. Everybody, men and women, greatly admired her beauty and her costly attire, but they were puzzled as to who she was, and where she came from. A prince happened to be in the church on that day, and he, too, admired the beautiful maiden.
Just before the service ended, the girl stole from the church, went hurriedly home, took off her beautiful clothes and placed them back in the chest, which instantly shut and became invisible. She then rushed to the kitchen, where she discovered that the dinner was quite ready, and that the millet was gathered into the basket. Soon the stepmother came back with her daughter, and they were astounded to find the millet gathered up, dinner prepared, and everything else in order. A desire to learn the secret now began to torment the stepmother mightily.
Next Sunday everything happened as before, except that the girl found in the chest a silver dress, and that the prince felt a greater admiration for her, so much so that he was unable, even for a moment to take his eyes from her. On the third Sunday, the mother and daughter again prepared to go to church, and, having scattered the millet as before, she repeated her previous threats. As soon as they disappeared, the girl ran straight to her mother's grave, where she found, as on the previous occasions, the open chest and the same two doves. This time she found a dress made of gold lace, and she hastily clad herself in it and went to church, where she was admired by all, even more than before. As for the czar's son, he had come with the intention not to let her this time out of his sight, but to follow and see where she went. Accordingly, as the service drew near to its close, and the maiden withdrew quietly as before, the enamored prince followed after her. Marra hurried along, for she had none too much time, and, as she went, one of her golden slippers came off, and she was too agitated to stop and pick it up. The prince, however, who had lost sight of the maiden, saw the slipper and put it in his pocket. Reaching home, Marra took off her golden dress, laid it in the chest, and rushed back to the house.
The prince now resolved to go from house to house throughout his father's realm in search of the owner of the slipper, inviting all the fair maidens to try on the golden slipper. But, alas! his efforts seemed to be doomed to failure; for some girls the slipper was too long, for others too short, for others, again, too narrow. There was no one whom it would fit.
Wandering from door to door, the sad prince at length came to the house of Marra's father. The stepmother was expecting him, and she had hidden her stepdaughter under a large trough in the courtyard. When the prince asked whether she had any daughters, the stepmother answered that she had but one, and she presented the girl to him. The prince requested the girl to try on the slipper, but, squeeze as she would, there was not room in it even for her toes! Thereupon the prince asked whether it was true that there were no other girls in the house, and the stepmother replied that indeed it was quite true.
That very moment a cock flew onto the trough and crowed out lustily, "Kook-oo-ryeh-koooo! Here she is under this very trough!"
The stepmother, enraged, exclaimed, "Sh! Go away! May an eagle seize you and fly off with you!" The curiosity of the prince was aroused. He approached the trough, lifted it up, and, to his great surprise, there was the maiden whom he had seen three times in church, clad in the very same golden dress she had last worn, and having only one golden slipper.
When the prince recognized the maiden he was overcome with joy. Quickly he tried the slipper on her dainty foot. It not only fit her admirably, but it exactly matched the one she already wore on her left foot. He lifted her up tenderly and escorted her to his palace. Later he won her love, and they were happily married.
Petrovitch, Woislav M. Hero Tales and Legends of the Serbians. London: George G. Harrap and Company, 1917.