。
She cleans the room with a broom.
Literal
She [topic-は] broom [with-で] room [object-を] cleans.
で marks the instrument here — 'with [a broom].' 掃除する ('to clean') is a Sino-Japanese suru-verb for housework cleaning; native verbs like 掃く ('to sweep') are more specific. ほうき ('broom') is usually written in hiragana; the kanji 箒 is recognized but uncommon in everyday writing. Plain non-past 掃除する reads as either habitual ('she cleans') or future-bound, with context picking the reading.