Wow, Alexei, what long hair you have!
I can't see the blown up picture or see the small one close enough to identify which sister it is, but I do think it's Maria from the height, but it could be either Maria or Anastasia. If they're aboard the Kaiser's yacht, which year were they visiting him? It would be easier as we can identify which sisters were wearing their hair down at that time to narrow the selection down.
