Wexford Girl is a later form of the song, commonly found in America but rarely in England; it would, I suspect, be an Irish localisation of the earlier Oxford Girl.  You can find several American tune variants through my first link above; meanwhile, I'll have a look around here; I certainly have one, The Wexford Murder, which Fred Hamer got from Walter Church of Bedfordshire; Church had in his youth (turn of the 19th/20th century) briefly emigrated to Canada, and learnt it from Irish friends there.

Malcolm