。
She's from California.
Literal
She [topic-は] California [of-の] origin is.
~の出身 ('origin from X') is the standard formal way to state where someone is from — typically used for places of birth or where someone grew up, not where they live now. The construction is noun-of-noun: 'X of origin.' Casual speech often uses ~から来た ('came from X') instead, but ~の出身 is what you put on a résumé or in a self-introduction. Compare: アメリカ出身です (formal) vs アメリカから来ました (more casual). California, the home of much of Japan's pop-culture exposure to America (Hollywood, Silicon Valley, surf culture), is one of the most familiar US states to Japanese speakers.