。
She took off her jacket.
Literal
She [topic-は] jacket [object-を] took-off.
脱ぐ (ぬぐ, 'to take off clothing/shoes') is the opposite of 着る/履く/かぶる. Like the 'putting on' verbs, 脱ぐ is used for all body zones. 上着 (うわぎ) is an outer garment — jacket, coat, or blazer.