I don't own this pony but I may place my winning varient vote on a White Italian Lemondrop.
But here's why I specifically vote on this one. I imagine those over at Italy when they got the pony making instructions saw the original lemondrop and where like "Purple drops of lemon? Who ever thought of that??" So they made a water themed pony

Really - she's a one of a kind because it's interesting there wasnt an elemental pony for Water!