The lyrics she performs are written as "Carterhaugh." Pronunciations and our interpretations of sounds vary all over.

My first and several subsequent hearings of Fairport Convention version of Tam Lin, I assumed the word was Carterhall. It was not until I read the lyrics could I actually hear the distinction in pronunciation.

Having lived in UK for over a decade, I still have trouble hearing distinctions. My husband's English pronunciation of the shwa "a" sound (ah) in many words, still sounds like "ar" to me.