Nell demos do not exist. since she was just making singles throughout her career and was already established with the record company through Rocky people (i.e. Richard Hartley who was a producer there and among others) She had no need to produce demos. The singles were written all by Hartley and Brian Thompson and were finished in the studio.
I will say several versions of most songs were produced but they aren't demos. Fever has several versions, (original & disco) and Do the Swim has many versions as well. Most of them are downloadable here.
Yeah, I have them all. Thanks for the info!
There's always time to make an album, Little Nell