I own Beautiful Girls 4. I have never seen Sonia in any other movie. A lot of Euro girls work under different names, so it's possible she's done movies using a different alias. Of course, it's also possible that Beautiful Girls 4 was her only movie.
A couple of weeks ago ratman wanted to know if Sonia appeared in any other movies besides Beautiful Girls 4:
Even Speelie, who is one of the best at identifying Euro girls, didn't know of any other movie appearances by Sonia.
As you already know, Steve Holmes is one of the guys in Sonia's scene in Beautiful Girls 4. Maybe Steve knows of other movies she has done, or perhaps he can give you another alias that she works under. Steve's a nice guy, and I'm sure he'll answer you if you e-mail him.
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