Some websites say that Harlequin is in fact a breed, originating in France and weighing about 6-8 pounds with the ideal being 7.5. The coloration of that breed can also be “Magpie”, where the second color is white rather than orange. (so the rabbit would be black and white patterned instead of black and orange) You can view this information on Wikipedia(dot)com, Rabbitbreeders(dot)us, ect. While some sites claim that Harlequin is just a coloration. In my opinion I guess Harlequin is a breed. But Harlequin is also a color (You could have a harlequin colored holland lop).
Sometimes animal breeds can be confusing! 
Whatever she is, she is harlequin colored. If she is a harlequin rabbit, she most likely would not be pure bred. Pure breds should have the color split down the middle so half the face and is one color and the other half is a different color, like so:
It’s very hard to say, I don’t think anybody can tell you for sure. It’s hard to say but she sure is gorgeous!