。
She has a rough way of speaking.
Literal
She [topic-は] word-use [subject-が] rough.
Another XはYが attribute frame, this time naming a flaw rather than a trait. 言葉使い ('use of words, manner of speaking') — also written 言葉遣い in more formal text — covers vocabulary choice, register, politeness level, and tone all at once. 荒い ('rough, wild, coarse') applied to speech suggests crude vocabulary, brusque phrasing, or aggressive delivery — broadly, the kind of language that breaches expected politeness. In Japanese culture, where calibrating speech register to relationships is itself a core social skill, criticizing someone's 言葉使い is a heavier judgement than the closest English equivalents would suggest.