、。
She seems to be pretty good, but she's not first-rate, you know.
Literal
She [topic-は] quite does [seems-ようだ] [but-が], first-class isn't [right?-ね].
なかなかやる is a fixed colloquial expression — やる ('do') with なかなか forms a casual idiom for 'is pretty capable / not bad at all,' often said with a tone of grudging respect. The clause-final が ('but') sets up the contrast that follows: 一流じゃない ('not first-rate'). The sentence-final ね softens the assertion into a shared observation, inviting agreement. 一流 ('first-class, top-tier') is a slightly elevated noun for excellence; the negation じゃない is the casual contraction of ではない.