。
She cut the apple in half.
Literal
[topic-は] apple [object-を] half [into-に] cut.
The productive 'cut into [parts]' pattern is at work here: object + を + [number] + に + 切る. The に marks the resulting state of division — 'into halves.' The same structure scales to any number of pieces (三つに切る 'cut into three'); the adverbial form covers manner instead (細かく切る 'cut finely'). リンゴ is conventionally written in katakana even though the kanji 林檎 exists, since fruit names often go in katakana for visual clarity in cookbooks and casual writing.