It's because she has danced a great many ballets, all different styles, and has had successes in all of them. From Balanchine to Forsythe to Petit to most of the classical roles. Aurora, Giselle, Nikya, Romeo and Juliet, now Swan Lake. That's my definition of a diverse ballerina.
Sure, in my definition you also need to be convincing in all. You can dance the whole repertory but turn it in the same show all over - that's not what I call being diverse.