I've come across one image recently, though - this one:
[caption id="attachment_5309" align="alignnone" width="390"]
Bibliothèque Nationale de la France, Manuscript Latin 7330, liber astrologiae Georgii Zapari Zothori Fenduli, c 1301-1400. Fol. 30r, if I've interpreted things correctly. Permalink to the page in the digital BNF.
That lady is not using a distaff, but instead she's holding two filled spindles in her left hand, and plies the threads together with the spindle hanging below her right hand.
Now that's definitely a rare picture, and a method I do have to try! Anyone here ever tried plying this way already? Or do you know more pictures like this? (Or, while I'm already blegging, images of spinners not in the classical one-arm-fully-extended position?)