Her albums can be found second hand and at least some are available on cd. She has two existing volumes of autobiography which are, I think, out of print but worth tracking down. The first is Midnight Baby and the second is Bogtrotter. Reading them and you get a flavour of what we would now call an abusive childhood and which directly informs the lyrics on her first two albums, On My Way to Where and Mythical Kings and Iguanas.
I had the great pleasure of seeing her perform in Glasgow around 1977 with more or less the same set I think as the Live at Carnegie Hall LP.