。
She's at the Gorilla Foundation research center in California.
Literal
She [topic-は] California [of-の] Gorilla-Foundation research-center [at-に] is.
This sentence almost certainly refers to Koko (1971–2018), the western lowland gorilla famously taught a vocabulary of hand signs at the Gorilla Foundation in Woodside, California. Founded by Dr. Penny Patterson in 1976, the Foundation became a long-running research project on primate language acquisition and emotional life — Koko was widely covered in Japanese press, books for children, and translations of Patterson's writings, making her a familiar figure in Japan as a touchstone of human-animal communication. 財団 ('foundation') and 研究所 ('research institute') are both Sino-Japanese compounds frequently found in institution names. The に + いる construction marks animate location: 'is in/at [place].'