。
Her physical condition is gradually improving.
Literal
She [topic-は] gradually condition [subject-が] [is-getting-better-よくなっています].
体調 (taichō, 'physical condition') is a useful Japanese compound for talking about general health-state without being specific about symptoms — 体調がいい/悪い ('feeling well / unwell'), 体調を崩す ('fall ill, take a turn'). The doubled-subject frame 彼女は体調がよくなる ('as for her, condition gets better') is one of Japanese's classic 'big topic, smaller subject' structures: an outer は marks the person, an inner が marks the property of theirs that's changing. The polite ~ています ending makes this fit for talking to a doctor, an acquaintance, or anyone for whom plain ~ている would be too casual.