As a relative latecomer to the folk scene, I never thought much of Ray at first as I'd heard no more than 1 or 2 songs from recordings others had played for me. Then I saw her judging at a small festival in the Scottish Borders, then again at a concert with Cilla and Archie and since then I've gone on to buy every one of her recordings I could find.
She's a one-off, as Brian says: she's got a way with the big ballads but can also effortlessly switch from profoundly moving to hilarious within the space of an intro to a song.
I agree with many of the other posters in that she's been criminally under-appreciated, especially by the high-flying youngsters. Get better soon Ray, I haven't seen you anything like often enough yet...