。
She is very busy.
Literal
She [topic-は] very is-busy.
大変 here is the adverbial intensifier 'very, extremely' — directly modifying the i-adjective 忙しい ('busy'). Note that the plain non-past form covers both 'present' and 'future' in Japanese; tense is generally about completed-vs-ongoing rather than past-vs-future, so 忙しい reads as 'is busy [now / habitually / going forward].'