So I used to work in college admissions, and this is a name that I've puzzled over for a while. It was a girl's first name. I assume it was her mother's/someone important's maiden name, used as a first name.
My guess is it was pronounced "shehz-NEE." But your guess is as good as mine.
The upside? It makes Clemens' parents look like they had good taste.

Re: Szcznie
Her last name ended in --son, I think. Which isn't to say it couldn't have been a cultural name. I just remember that making me think, "well, at least one of her parents should've known better."
It looked like a Polish/Eastern European last name. I've known people with the last name Vrbka and Kutchkau (pronounced KOOTCH-kah). I think Ellis Island really screwed some people over...
This is what I thought too!
It's Croation. A variation of Susan. I actually went to school with a Szcznie and a Snjezana--Susan and Susannah--they were sisters: )
ETA: your pronunciation is basically correct. Snjezana is pronounced Shnejsh-nah.
Seriously? That fascinates me. I would have never guessed that was a "real" name. You just broadened my horizons.