。
I don't think she's suited for that job.
Literal
She [topic-は] that work [target-に] not-suited [quotative-と] think.
~と思う ('I think that') wraps the assessment, softening it by marking the claim as the speaker's opinion rather than a stated fact. Japanese frequently embeds judgments inside ~と思う to avoid sounding too direct or assertive — particularly when the judgment is critical or negative. 適していない (negative of 適している) carries the actual assertion; the と思う frame defangs it. The plain form ~と思う (versus polite ~と思います) keeps the register casual.