。
She tried to push her opinion through.
Literal
She [topic-は] her own opinion [object-を] push-through [tried to-ようとした].
意見を通す ('to push one's opinion through, get one's view to prevail') belongs to a productive family of [X]を通す idioms where 通す ('pass through') figuratively means forcing something through to acceptance: 主張を通す, 我を通す, 言い分を通す. ~ようとする ('to try to') wraps the action as an attempt; the past ~ようとした often implies the attempt may not have fully succeeded.