Confirmation from balletomaniac -- CriticalDance.
"Ms. Osipova is, simply put, remarkable. From her first steps after she leaves her front door in Act I, she seems never to be on the ground. Ms. Osipova looks like a pixie; and dances lighter than air. Whenever she leaves the ground (literally), she rises up and never seems to come back down to earth. And her jumps are not energy explosions – she moves through air as effortlessly as the petal of a flower borne by the breeze."
Please take a look at balletomaniac's complete review of many of the 'Russian' dancers' performances and the fine performances of many others.
http://www.ballet-dance.com/forum/viewt ... 517#198517
As for whether the young Natalia Osipova can handle the portrayal of such mature and serious subject matter as "Giselle' and "La Sylphide" requires, I would say accept her for what she is -- a young, highly talented, sincere, totally lovable performer -- giving it everything that she can, and that is a lot! Why rush the 'maturity'. If its there fine. Otherwise her youthful, lovable innocence and sincerity should do the job just fine.