Elliot - I've only ever known it as a boy's name
Darcy - not my taste, but never done Darcey Bussell any harm.
Scarlett - nice on a very beautiful, confident young woman, doesn't feel right to me for a child or old person, and definitely wouldn't work on a shy, dumpy, geeky kid
Madison - pretty, but a bit common, sorry.
Phoebe - lovely. Popular, if that bothers you either way.
Aurora - beautiful. IMO not too out-there, but I see that others don't agree
Matilda - I had a cat called Matilda, so it doesn't feel right for a person
Elise - pretty, but I prefer Elisa
Xanthe - pretentious. That's because I don't know how to say it, so it makes me feel thick, though.
Trinity - Matrix.
Tabitha - definitely cat.