。
She gave her speech with gestures.
Literal
She [topic-は] gestures [object-を] mixing-in [while-ながら] gave-a-speech.
身振り (みぶり, 'gestures, body movements') combined with を交える ('to mix in, to intersperse') forms a natural phrase for incorporating gestures into communication. The ~ながら connects two simultaneous actions by the same subject: she was gesturing while delivering the speech. 演説する (えんぜつする) specifically means to give a formal speech or oration — more elevated than 話す or スピーチする.