Hmmm... hard to say. I don;t know too many people from that culture, but I'd guess around 20-23. Definitely less than 25. If I'm wrong, let me know.
Oh, and I know this one Russian lady in one of my classes who looks really young but is married, has a kid, and has a very refined English accent. Of course, I can't ask her age since that's impolite, but she doesn't seem to be a day over 22, heck, she looks almost 18! How do you tell age when there is no standard?
At any rate, Storm still looks youthful...