Sylvie - love, also Sylvia
Elowen - I really want to like this, it looks beautiful, but I think it sounds a bit clunky... I really love Arwen, not a nature name but has the same ethereal feel, I think.
Derwa - dislike
Derowyn - dislike
Asha - my sister's name, pretty
Robyn - not keen
I really love Iris, though it's getting popular now, and also have a bit of a soft spot for Fern. Rowan is also beautiful, and I don't think the Rowan Atkinson association would spring to mind with a girl. I also like Camellia, Calla, Laurel, Aria, Opal, Eden, Violet / Viola. Other suggestions: Heather, Coral / Coralie, Jasmine, Delta, Tansy, Fleur, Ondine, Ilana.