Ответ: She isn't taking a shower at the moment.
Краткое пояснение: Чтобы образовать отрицательное предложение в Present Continuous, используйте форму to be (is/are/am) + not + глагол с окончанием -ing.
She isn't taking a shower at the moment.
Ответ: She isn't taking a shower at the moment.