If you can remove the spool itself, Denise, you'll find a flexible driveshaft (a bit like a coiled cable) that connects the engine to the spool. The chances are that it has disconnected itself and you'll need to check if it has snapped or simply come adrift. It often happens if the fixing screws come loose, allowing the engine to disconnect itself from the drive cable. PS you're lucky if you have weeds to cut...over here they haven't appeared above the layers of ice...!
John
April 2008