。
She picked up her book.
Literal
She [topic-は] her own book [object-を] hand [in-に] took.
手に取る (literally 'to take into one's hand') is the fixed verb-particle frame for 'to pick up, to take hold of (an object).' More vivid than 取る on its own, which can sound abstract — 手に取る emphasizes the physical action of handling. The reflexive 自分の clarifies that the book is hers, not someone else's — a small touch that anchors a possibly ambiguous scene.