I rather liked Melanie and had quite a few of her albums in my old vinyl collection. She, like Donovan, seemed to be almost inseparably connected in people's minds with flower power, and this earned her contempt in some quarters which was kind of sad.
One thing I noticed was that on some songs she sounds a lot like Buffy Sainte-Marie...not the distinctive vibrato, but something else in the vocal tone. I've never heard anyone else who did.
Melanie did some interesting stuff in the early 80's, but as I recall it did not garner much attention, at least not in Canada. I suspect she would have done much better in Europe than in North America.
Thanks for the links!