。
She made a hole in her blouse.
Literal
She [topic-は] blouse [in-に] hole [object-を] opened.
穴をあける ('to make a hole, open a hole,' literally 'open a hole') is the standard collocation for piercing or tearing something. The に marks the surface or object receiving the hole — 'in the blouse.' あける without kanji can mean 開ける ('open'), but here in the context of 穴 ('hole') the verb has its specific 'pierce, perforate' nuance. Accidental or deliberate, the sentence reads as a discrete event of damage.