。
She gives each child two apples.
Literal
She [topic-は] child 1-person [target-に] apples 2-pieces [each-ずつ] is-distributing.
A clean illustration of the distributive ~ずつ ('each, apiece, at a time'). The pattern [number+counter]+ずつ marks an even allocation: 一個ずつ ('one apiece'), 二人ずつ ('two at a time'). Combined with 子供一人に ('to each one child'), the sentence sets up a one-to-many distribution. 分ける ('divide, share out') is the action verb; the progressive ~ている marks an ongoing or routine distribution. 個 is the generic counter for small round/discrete objects, used here for apples.