the French version, “The Lost Children”, takes it a little step further. The witch is actually the devil’s wife who tries to put one of the children on a sawhorse. She wants the children to bleed slowly. The children pretend not to know how to get on, and so the devil’s wife demonstrates. As she is lying down, the children slice her throat and are able to escape.
About those Grimm Brothers: Forgotten Tales of the Brothers Grimm at http://publicdomainreview.org/2012/12/20/the-forgotten-tales-of-the-brothers-grimm/. A 42-page Grimm Tale Study Guide is also available at http://www.tlsfrankfurt.com/tls/wp-content/uploads/2012/09/A_Grimm_Tale_Studyguide.pdf.