。
She took down a book from the shelf.
Literal
She [topic-は] shelf [from-から] book [object-を] one-volume took-down.
Two structural points. から ('from') marks the source of motion — the shelf is where the book came from. 一冊 is the counter for bound volumes (books, magazines, manga); the counter goes after the noun-を pair, in the standard Japanese pattern [noun]+[particle]+[number+counter]+[verb] (本を一冊 'one book,' lit. 'a book, one-volume'). 降ろす specifically means 'bring down from above'; the more general 下ろす is identical in pronunciation and overlaps in meaning, but 降ろす leans toward 'take down off' (a shelf, a vehicle).