BOGRAT - have you tried contacting the Derbyshire Scouts county caving adviser Nick Coward. He was on this forum some time ago but I can't remember his posting name. He may know of someone who holds a permit that covers caving for girl guides as well as scouts.
I know that a couple of years ago,my scout caving team ( Leicestershire Scouts County Caving Team) ran several trips for Derbyshire guides in Carleswark and Giants.
You might be able to contact Nick Coward on
caving@derbyshirescouts.org
Cheers
Paul C