The Complete Book of Muslim & Parsi Names by Maneka Gandhi & Ozair
Husain gives Shaziah as a name derived from Arabic meaning "rare, extraordinary, miraculous."
Meanwhile that book give Shaziy and
A Dictionary of Muslim Names by Salahuddin
Ahmed gives
Shazi as a name derived from Arabic meaning "fragrant."
I would guess Shazia is a variation of either Shaziah or
Shazi, but at this remove it's hard to tell which one is the basis for her name.