。
She's gradually recovering.
Literal
She [topic-は] gradually is-recovering.
回復 ('recovery') is one of those Sino-Japanese workhorse compounds — 回 ('return, turn') + 復 ('return, restore') — where both kanji push toward 'restore to a previous state.' Used for recovery from illness, injury, economic downturn, or even data restoration in computing. Combined with 次第に ('gradually'), the present progressive ~ている emphasizes that the recovery is an ongoing process, not yet complete.