。
She's worried about her health.
Literal
She [topic-は] her [genitive-の] health [object-を] is-worrying.
心配する takes its object with を, unlike English 'worry about' which uses a preposition — a learner has to memorize that worry in Japanese is transitive. The ~ている form here marks an ongoing state (she has been and continues to be worried), not a momentary action. Whose health is in fact ambiguous: the doubled 彼女 reads as stilted, but in natural Japanese the second 彼女 would be dropped, and context would resolve whose health is at issue.