Symbolism, Imagery, Allegory
Back in the day, people had to spin their own thread and yarn and stuff from scratch. And by "people" we mean "women." It was apparently tedious work, and so we get tales in which women try to get out of it by any means necessary. Some critics even argue that spinning was such an important part of women's lives that they did it during most of their free time. And to pass the time while spinning, they would tell tales…that were, sometimes, about spinning. Yikes.
We get glimpses of spinning (and the mixed feelings about it) in a handful of tales. In "Rumpelstiltskin," a poor miller lies about his daughter's ability to spin straw into gold, and thus puts her life on the line. The king at first threatens her life if she cannot fulfill this task, but then offers to marry her when she does. You know, because marrying your homicidal captor constitutes a happy ending and all.
Similarly, in "The Three Spinners," a mother beats her daughter because she is "a lazy maiden who did not want to spin, and no matter what her mother said, she refused to spin" (The Three Spinners.50). When the queen passes by and inquires about the ruckus, the mother makes an exaggerated claim about her daughter's ability to spin tons of flax, which of course the maiden can't pull off. Three ugly old women help her accomplish this monumental task, and at the wedding they each say that spinning is what has made them ugly, thus getting the maiden off the hook forever. The moral of the story seems to be that marrying a prince is nice, but no longer being forced to spin is even nicer, especially if it means you'll stay pretty.
In "The Lazy Spinner," the whole point of the story is also about getting out of spinning. The main female character is Lazy-with-a-capital-L: "Whenever her husband gave her something to spin, she never finished it, and whatever she did spin, she did not wind but left it tangled on the bobbin" (The Lazy Spinner.41). She then tells her husband to chop wood to make her a reel so she can actually finish her spinning, but she uses that opportunity to creepily whisper a prophecy about how both chopping wood and spinning will cause death. She manages to get out of spinning, but the tale ends: "you yourself must admit that his wife was a nasty woman" (The Lazy Spinner.42). Not spinning is a plus, but not wanting to spin makes you nasty? Mixed messages, much?
Oh, and Brier Rose? Yeah, spinning didn't work out so well for her either, seeing as she pricked her needle on a spindle and took the longest nap ever. The subjugated heroine in "Mother Holle" also has a bad time with spinning: "Every day the poor maiden had to sit near a well by the road and spin and spin until her fingers bled" (Mother Holle.88).
So spinning is this awful task and it makes you ugly and it's required for every woman to do…we're not getting a good vibe here. One notable counterexample is "Spindle, Shuttle, and Needle," wherein the good, pious girl spins and spins and attracts a wealthy husband because she's so hardworking (maybe he doesn't know that the ugly comes later).
Spinning can lead to snagging a desirable spouse or riches (as in "The Three Spinners," "Rumpelstiltskin," and "Mother Holle"), but we're not sure if that makes spinning a good thing or not, given all the other bad stuff that comes with. So while spinning is a sure sign of womanhood in these tales, it's both a blessing and a curse.