Big fan of Xanthe. I love that it’s established but has that zippy X! Definitely a cool, artsy girl name. In England it’s got a sort of posh party girl vibe I’d say, used by ‘upper class’ sorts who might also use India, Saffron, or Ludo. Jasmine from this year’s Bake Off has a sister named Xanthe.
Xanthe Leilani - cool, emphasises the artsy vibe, bit of a mouthful perhaps?
Xanthe Violet - lovely, I would genuinely use this myself 
classic with a twist!
Xanthe Marina - full posh party girl mode, I LOVE it, lovely flow and really summery vibes
Xanthe Amaris - international and intriguing, she sounds like she could be a spy or a supermodel (or both)!