While "Spinster" has come to mean an older, unmarried woman, it actually used to mean a woman who spun (on a spinning wheel), and this was typically the occupation of younger, unmarried women.
See, among other places: https://www.merriam-webster.com/words-at-play/spinster-meaning-origin
Edited to add: this was posted by a married spinster, who could now be said to be "older" if not yet "elderly."