。
She's healthy enough to work now.
Literal
[topic-は] now can-work [extent-ほど] healthy [copula-だ].
~ほど here marks the extent or degree of the predicate that follows — 'healthy to the extent that she can work.' This pairs nicely with potentials (働ける = 'can work') because the threshold being measured is itself an ability. もう ('now, already') signals a positive turn — she had been ill or recovering; the sentence is reassurance that she's past that point. Note that 健康だ uses 健康 as a な-adjective; in noun position (健康に注意する 'mind one's health') it behaves as a noun.