She had her hair cut short.

Literal

She [topic-は] hair [object-を] short cut [had-someone-do-てもらった].

~てもらう is the canonical 'have someone do (for me).' For services like haircuts, dental work, or photography, Japanese reaches for this construction routinely — a notable contrast with English, which often uses passive ('had her hair cut') or active without specifying who did it.