Right, I've got that one on a comp. plus a few others, although that's the best.
Yep, got that one too - very jazz-funky more than rare soul in my book but still a top tune:She was signed by Capitol Records in the late 1970s and in an attempt to broaden her appeal she cut the album Life, Love and Harmony, an album of soulful, funky dance cuts that included the track "Sunshine", which was to become one of her most sought-after recordings (albeit among supporters of the rare soul scene with whom she would not usually register).
Sunshine - Nancy Wilson
I can recommend the album featured on the YT which is where I got the track - the other two volumes are pretty good too - jazz-funk with an emphasis on the jazz.
As to Nancy Williams - did find a couple by her on YT Gassy, very nice too.