。
She spoke using gestures.
Literal
She [topic-は] gestures [object-を] mixing-in [then-て] spoke.
ジェスチャー is the English loanword 'gesture,' written in katakana. It coexists with the native 身振り (みぶり), though ジェスチャー tends to feel more international or presentation-oriented, while 身振り feels more physical and organic. The construction ~を交えて話す ('to speak while mixing in X') is a versatile pattern that works with any supplementary element: ユーモアを交えて ('with humor'), 具体例を交えて ('with concrete examples').