The Moth by Catherine Cookson

Loved this book! (and if you get the chance to see the BFS film version (Jack Davenport and Juliet Aubrey 1997 its well worth a viewing and is faithful to the book). There is some cussing of the British variety (calling into question one's parentage mainly) but no sex. It's a classic "two people who arent social equals fall in love...". Great story
And by the way, if a hero doesn't end up half dead, blind, scarred and crippled by the end of a CC novel someone hyjacked it!