This is a book set in Wales, a lot of focus on the Moors of Wales. Possibly a YA love story book. About a royal and a civilian… I believe a prince and a “common” girl. One of the characters, I believe the girl, talks of a string that connects the two together and somewhere in the story the string gets cut.
Could this be one of Catherine Fisher’s books?
I don’t think so… I read this in the early 90’s, and the ones on her site from this time period don’t ring a bell.